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Angles/ Slopes of Parallel and Perpendicular Lines: Geometry Escape Room - Math

Angles/ Slopes of Parallel and Perpendicular Lines: Geometry Escape Room - Math

This breakout escape room is a fun way for students to test their skills with finding the angles and slopes of parallel and perpendicular lines in slope-intercept form. Contents: ♦ Teacher Instructions and FAQ ♦ 3 Levels to decode: Multiple Choice, Tarsia Puzzle, and Message Decoder ♦ Student Recording Sheet and Teacher Answer Key ♦ Link to an optional, but recommended, digital breakout room
ScienceSpot
Polygon angles investigation

Polygon angles investigation

A complete lesson with a focus on angles as variables. Basically, pupils investigate what angle relationships there are when you overlap a square and equilateral triangle. A good opportunity to extend the topic of polygons, consider some of the dynamic aspects of geometry and allow pupils to generate their own questions. Prior knowledge of angles in polygons required. Activities included: Starter: A mini-investigation looking at the relationship between two angles in a set of related diagrams, to recap on basic angle calculations and set the scene for the main part of the lesson. Main: A prompt (see cover image) for pupils to consider, then another prompt for them to work out the relationship between two angles in the image. A slide to go through the answer (which isn’t entirely straight forward), followed by two animations to illustrate the dynamic nature of the answer. A prompt for pupils to consider how the original diagram could be varied to generate a slightly different scenario, as a prompt for them to investigate other possible angle relationships. I’ve not included answers from here, as the outcomes will vary with the pupil. The intention is that pupils then investigate for themselves. Plenary: Another dynamic scenario for pupils to consider, which also reinforces the rules for the sum of interior and exterior angles. Please review if you buy as any feedback is appreciated!
danwalker
Interior and exterior angles of polygons

Interior and exterior angles of polygons

A more challenging lesson, mostly on polygon angles, with a focus on considering alternative approaches to less formulaic questions. Designed to come after pupils have spent time calculating interior and exterior angles. Starter: A prompt for pupils to try to accurately draw a regular pentagon and regular hexagon. The intention is that they could use a protractor and knowledge of interior or exterior angles to do this (although they could use compass methods, if they know them). Main: A prompt and basic question on using the fact that the interior and exterior angle at any vertex sum to 180 degrees. Two related questions for pupils to consolidate, but also build towards the next task. An image of a square and regular pentagon overlapping for pupils to consider. Firstly, a prompt for them to identify as many shapes as they can, then a prompt for them to find the value of a marked angle. There are quite a few ways of doing this, and the intention is that pupils try to find these (as many as possible). I’ve then animated (but without words) six possible methods of obtaining an answer, so the task could be flipped into “describe the method” instead of “find the angle”. Pupils could then make a poster showing different methods, or collaborate and discuss their approaches if you didn’t use the flipped approach. A second image to be considered in a similar way. Plenary: A table showing shapes by number of sides, interior and exterior angle (if regular) together with a set of related questions to probe for any misconceptions. No printing needed! Please review if you buy as any feedback is appreciated!
danwalker
Exterior angles of polygons

Exterior angles of polygons

A complete lesson on exterior angles of polygons. I cover exterior angles after interior angles, so I should point out that the starter does rely on pupils knowing how to do calculations involving interior angles. See my other resources for a lesson on interior angles. Activities included: Starter: Some recap questions involving interior angles and also exterior angles, but with the intention that pupils just use the rule for angles on a line, rather than a formal definition of exterior angles (yet). Main: A “what’s the same,what’s different” prompt followed by examples and non-examples of exterior angles, to get pupils thinking about a definition of them. A mini- investigation into exterior angles. Prompts to establish and then prove algebraically that exterior angles sum to 360 degrees for a triangle and a quadrilateral. The proofs could be skipped, if you felt this was too hard. A worksheet of more standard exterior angle questions with a progression in difficulty. Plenary: A slide animating a visual proof of the rule, followed by a hyperlink to a different visual proof. Printable worksheets and answers included. I’ve also included suggested questions and extensions in the notes boxes at the bottom of each slide. Please review if you buy as any feedback is appreciated!
danwalker
Interior angles of polygons

Interior angles of polygons

A complete lesson on interior angles of polygons. Activities included: Starter: A slide showing examples and non-examples of interior angles, for pupils to think about a definition, followed by a set of images where pupils must identify any interior angles (sounds easy and dull, but isn’t!) Main: A recap of visual proofs of why the interior angles of a triangle sum to 180 degrees and those of a quadrilateral sum to 360 degrees, leading to the obvious question of “what next?” Prompts for the usual “investigation” into the sum of interior angles for polygons, by splitting into triangles. A set of questions designed to be done with mini whiteboards, starting with basic sums of interior angles, interior angles of regular polygons and finally a few variations (see cover image). A four-part worksheet (one page if printed two-a-side and two-sided) with a similar progression in difficulty. Plenary: A slide summarising the rules encountered, together with some key questions to check for any misconceptions. Printable worksheets and answers included. I’ve also included suggested questions and extensions in the notes boxes at the bottom of each slide. Please review if you buy as any feedback is appreciated!
danwalker
Basic Angle Facts Lesson

Basic Angle Facts Lesson

This was taught as a one hour lesson on angles on straight lines, around a point & vertically opposite angles. I taught this to a middle ability year 7 group and by the end most students were comfortable with the LO’s Differentiation is through increased difficulty and depth as the questions progress, I use the students’ confidence with the examples to set starting points. Included is: 1 Presentation 2 Printable Activity 3 Printable Extension 4 Exit Ticket with Feedback indicators I usually display the initial questions on the bard and only print the extension but have included all printable resources. Feedback is much appreciated :)
MrMatthewBracewell
Angles using parallel lines worksheet / homework with help sheet

Angles using parallel lines worksheet / homework with help sheet

This is a resource I created for my Year 6 maths set (high ability) which would be suitable for KS3 as well. There are a number of angles which the students have to calculate without measuring, based on rules regarding angles and parallel lines. There are two versions, one with more answers given, and this could be given in class or as a homework task depending on the support required. The helpsheet contains powerpoint slides taken from a resource published by @dwatson802 called Angles with Parallel and intersecting lines.
MrHawes8
Angles in a triangle

Angles in a triangle

Angles in a triangle worksheet with resources collated from Don Steward (https://donsteward.blogspot.co.uk/), CIMT and Diagnostic Questions
mrgunnmaths
Circle theorem and algebra

Circle theorem and algebra

Few questions I wrote where students have to set up and solve equations, using their knowledge of circle theorems. Please note on the handwritten sheet, I made a mistake. One of the cyclic quadrilaterals and simultaneous equations does not work, the equations are parallel. I usually sell it as “I have made one deliberate mistake”
steele1989
Volume Angles Trapeziums Bundle

Volume Angles Trapeziums Bundle

Volume Angles Trapeziums Bundle All answers are included. If bought independently, these 3 resources would cost £7, but I am offering them in this bundle for £5.50, a saving of 21%. To view items individually, please go to Maths Shop
Elsie99
GCSE 9-1 Geometry Questions (Bundle)

GCSE 9-1 Geometry Questions (Bundle)

These carefully selected compilations of exam questions have fully-worked solutions designed for students to go through at home, saving valuable time in class. Click 👉 tes.com/…/Exam Question Bundles… to download the other four bundles.<hr>I usually print these questions as an A5 booklet and issue them in class or give them out as a homework. I also make them available for a student who wants to do focused independent study on a topic.<hr>👍If you like this resource, then please rate it and/or leave a comment💬. If the rate-resource button on this page doesn’t work, then go to your ratings page by clicking 👉 www.tes.com/…/rate-resources…
Maths4Everyone
GCSE maths revision 1- 5

GCSE maths revision 1- 5

A collection of foundation maths resources aimed at post 16 learners in an FE setting but equally useful for all foundation maths students looking for revision practice. Tips for effective revision, a mathematical model of problem solving and revision opportunities for topics including: fractions, percentages (including % change), algebra, standard form to name a few. 11 topics included overall
drpallad
Maths Quiz

Maths Quiz

A maths quiz that tests multiple areas of the maths curriculum: Mental Maths Calculations involving decimals Money Shape Area and Perimeter BODMAS Measurements & Units Percentages Duration Speed Data Handling Circles
paultyler
Roll-a-topic GCSE foundation Geometry Revision

Roll-a-topic GCSE foundation Geometry Revision

A revision activity that can be used for KS3 or foundation GCSE pupils. Can be implemented in lots of ways. I ask pupils to get into pairs, take turns rolling two dice to form a co-ordinate and attempt to solve the corresponding question. Pupil put their initials on problems they have solved and after 30-45 minutes stop and count who has solved the most. Very engaging for year 10 and 11 foundation GCSE pupils. If you use this resource please leave a review! :)
prescott72
Corresponding and Alternate Angles (full lesson)

Corresponding and Alternate Angles (full lesson)

An animated powerpoint demonstrating the equivalence of corresponding and alternate angles. Includes a starter to recap angles on a straight line and in a full turn, three worksheets of increasing difficulty, and a game of pairs where students match diagrams with the size of the unknown angle and the rule used.
dsattaur
3D Trigonometry

3D Trigonometry

A worksheet with plenty of 3D Trig questions for students to try. Please let me know if you like it. Numerical answers are at the bottom.
RAGMaths
Illustrating properties of shapes

Illustrating properties of shapes

2 differentiated worksheets working towards mastery in identifying and illustrating properties of shapes, including parallel lines, equal sides, equal angles, right angles and perpendicular lines. Includes reasoning and problem solving questions.
spanni
IB Maths HL - Complete Notes

IB Maths HL - Complete Notes

Complete notes, without any option topics, just the main topics 1 to 6 This is a collection of all of the notes I have written for my IB Maths HL class. They are handwritten, concise notes, covering the whole course in 77 pages. Topic 1 - Algebra - 21 Pages Topic 2 - Functions - 10 Pages Topic 3 - Trigonometry - 6 Pages Topic 4 - Vectors - 10 Pages Topic 5 - Statistics & Probability - 10 Pages Topic 6 - Calculus - 20 Pages If you would like to see what you would be getting, you can download Topic 1 of IB SL or IB Math Studies for free. I hope you enjoy, and please ‘follow’, as I will be uploading other IB resources soon.
jwmcrobert
Circle theorems lesson 8

Circle theorems lesson 8

A complete lesson on the theorem that a perpendicular bisector of a chord passes through the centre of a circle. Assumes pupils can already use the theorems that: The angle at the centre is twice the angle at the circumference The angle in a semicircle is 90 degrees Angles in the same same segment are equal .Opposite angles in a cyclic quadrilateral sum to 180 degrees A tangent is perpendicular to a radius Angles in alternate segments are equal Tangents from a point are equal so that more varied questions can be asked. Please see my other resources for lessons on these theorems. Activities included: Starter: An animation reminding pupils about perpendicular bisectors, with the intention being that they would then practice this a few times with ruler and compass. Main: Instructions for pupils to investigate the theorem, by drawing a circle, chord and then bisecting the chord. Slides to clarify the ‘two-directional’ nature of the theorem. Examples of missing angle or length problems using the theorem (plus another theorem, usually) A similar set of eight questions for pupils to consolidate. An extension prompt for pupils to use the theorem to locate the exact centre of a given circle. Plenary: An animation of the proof without words, the intention being that pupils try to describe the steps. Printable worksheets and answers included. Please review if you buy, as any feedback is appreciated!
danwalker
Circle theorems lesson 7

Circle theorems lesson 7

A complete lesson on the theorem that tangents from a point are equal. Assumes pupils can already use the theorems that: The angle at the centre is twice the angle at the circumference The angle in a semicircle is 90 degrees Angles in the same same segment are equal .Opposite angles in a cyclic quadrilateral sum to 180 degrees A tangent is perpendicular to a radius Angles in alternate segments are equal so that more varied questions can be asked. Please see my other resources for lessons on these theorems. Activities included: Starter: Instructions for pupils to discover the theorem, by drawing tangents and measuring. Main: Slides to clarify why this theorem usually involves isosceles triangles. Related examples, finding missing angles. A set of eight questions using the theorem (and usually another theorem or angle fact). Two very sneaky extension questions. Plenary: An animation of the proof without words, the intention being that pupils try to describe the steps. Printable worksheets and answers included. Please review if you buy, as any feedback is appreciated!
danwalker
Circle theorems lesson 6

Circle theorems lesson 6

A complete lesson on the alternate segment theorem. Assumes pupils can already use the theorems that: The angle at the centre is twice the angle at the circumference The angle in a semicircle is 90 degrees Angles in the same same segment are equal .Opposite angles in a cyclic quadrilateral sum to 180 degrees A tangent is perpendicular to a radius so that more varied questions can be asked. Please see my other resources for lessons on these theorems. Activities included: Starter: Some basic questions to check pupils know what the word subtend means. Main: Animated slides to define what an alternate segment is. An example where the angle in the alternate segment is found without reference to the theorem (see cover image), followed by three similar questions for pupils to try. I’ve done this because if pupils can follow these steps, they can prove the theorem. However this element of the lesson could be bypassed or used later, depending on the class. Multiple choice questions where pupils simply have to identify which angles match as a result of the theorem. In my experience, they always struggle to identify the correct angle, so these questions really help. Seven examples of finding missing angles using the theorem (plus a second theorem for most of them). A set of eight similar problems for pupils to consolidate. An extension with two variations -an angle chase of sorts. Plenary: An animation of the proof without words, the intention being that pupils try to describe the steps. Printable worksheets and answers included. Please review if you buy, as any feedback is appreciated.
danwalker
Circle theorems lesson 5

Circle theorems lesson 5

A complete lesson on the theorem that a tangent is perpendicular to a radius. Assumes pupils can already use the theorems that: The angle at the centre is twice the angle at the circumference The angle in a semicircle is 90 degrees Angles in the same same segment are equal .Opposite angles in a cyclic quadrilateral sum to 180 degrees so that more varied questions can be asked. Please see my other resources for lessons on these theorems. Activities included: Starter: Some basic recap questions on theorems 1 to 4 Main: Instructions for pupils to discover the rule, by drawing tangents and measuring the angle to the centre. A set of six examples, mostly using more than one theorem. A set of eight similar questions for pupils to consolidate. A prompt for pupils to create their own questions, as an extension. Plenary: A proof by contradiction of the theorem. Printable worksheets and answers included. Please do review if you buy, as any feedback is greatly appreciated!
danwalker
Circle theorems lesson 4

Circle theorems lesson 4

A complete lesson on the theorem that opposite angles in a cyclic quadrilateral sum to 180 degrees. Assumes that pupils have already met the theorems that the angle at the centre is twice the angle at the circumference, the angle in a semicircle is 90, and angles in the same segment are equal. See my other resources for lessons on these theorems. Activities included: Starter: Some basics recap questions on the theorems already covered. Main: An animation to define a cyclic quadrilateral, followed by a quick question for pupils, where they decide whether or not diagrams contain cyclic quadrilaterals. An example where the angle at the centre theorem is used to find an opposite angle in a cyclic quadrilateral, followed by a set of three similar questions for pupils to do. They are then guided to observe that the opposite angles sum to 180 degrees. A quick proof using a very similar method to the one pupils have just used. A set of 8 examples that could be used as questions for pupils to try and discuss. These have a progression in difficulty, with the later ones incorporating other angle rules. I’ve also thrown in a few non-examples. A worksheet of similar questions for pupils to consolidate, followed by a second worksheet with a slightly different style of question, where pupils work out if given quadrilaterals are cyclic. A related extension task, where pupils try to decide if certain shapes are always, sometimes or never cyclic. Plenary: A slide showing all four theorems so far, and a chance for pupils to reflect on these and see how the angle at the centre theorem can be used to prove all of the rest. Printable worksheets and answers included. Please review if you buy as any feedback is appreciated!
danwalker
Circle theorems lesson 3

Circle theorems lesson 3

A complete lesson on the theorem that angles in the same segment are equal. I always teach the theorem that the angle at the centre is twice the angle at the circumference first (see my other resources for a lesson on that theorem), as it can be used to easily prove the same segment theorem. Activities included: Starter: Some basic questions on the theorems that the angle at the centre is twice the angle at the circumference, and that the angle in a semi-circle is 90 degrees, to check pupils remember them. Main: Slides to show what a chord, major segment and minor segment are, and to show what it means to say that two angles are in the same segment. This is followed up by instructions for pupils to construct the usual diagram for this theorem, to further consolidate their understanding of the terminology and get them to investigate what happens to the angle. A ‘no words’ proof of the theorem, using the theorem that the angle at the centre is twice the angle at the circumference. Missing angle examples of the theorem, that could be used as questions for pupils to try. These include more interesting variations that incorporate other angle rules. A set of similar questions with a progression in difficulty, for pupils to consolidate. Two extension questions. Plenary: A final set of six diagrams, where pupils have to decide if two angles match, either because of the theorem learnt in the lesson or because of another angle rule. Printable worksheets and answers included. Please do review if you buy as any feedback is greatly appreciated!
danwalker
Circle theorems lesson 2

Circle theorems lesson 2

A complete lesson on the theorem that the angle in a semicircle is 90 degrees. I always teach the theorem that the angle at the centre is twice the angle at the circumference first (see my other resources for a lesson on that theorem), as it can be used to easily prove the semicircle theorem. Activities included: Starter: Some basic questions on the theorem that the angle at the centre is twice the angle at the circumference, to check pupils remember it. Main: Examples and non-examples of the semicircle theorem, that could be used as questions for pupils to try. These include more interesting variations like using Pythagoras’ theorem or incorporating other angle rules. A set of questions with a progression in difficulty. These deliberately include a few questions that can’t be done, to focus pupils’ attention on the key features of diagrams. An extension task prompt for pupils to create their own questions using the two theorems already encountered. Plenary: Three discussion questions to promote deeper thinking, the first looking at alternative methods for one of the questions from the worksheet, the next considering whether a given line is a diameter, the third considering whether given diagrams show an acute, 90 degree or obtuse angle. Printable worksheets and answers included. Please do review if you buy as any feedback is greatly appreciated!
danwalker
Angles in a quadrilateral

Angles in a quadrilateral

A complete lesson on the interior angle sum of a quadrilateral. Requires pupils to know the interior angle sum of a triangle, and also know the angle properties of different quadrilaterals. Activities included: Starter: A few simple questions checking pupils can find missing angles in triangles. Main: A nice animation showing a smiley moving around the perimeter of a quadrilateral, turning through the interior angles until it gets back to where it started. It completes a full turn and so demonstrates the rule. This is followed up by instructions for pupils to try the same on a quadrilateral that they draw. Instructions for pupils to use their quadrilateral to do the more common method of marking the corners, cutting them out and arranging them to form a full turn. This is also animated nicely. Three example-problem pairs where pupils find missing angles. Three worksheets, with a progression in difficulty, for pupils to work through. The first has standard ‘find the missing angle’ questions. The second asks pupils to find missing angles, but then identify the quadrilateral according to its angle properties. The third is on a similar theme, but slightly harder (eg having been told a shape is a kite, work out the remaining angles given two of the angles). A nice extension task, where pupils are given two angles each in three quadrilateral and work out what shapes they could possibly be. Plenary: A look at a proof of the rule, by splitting quadrilaterals into two triangles. A prompt to consider what the sum of interior angles of a pentagon might be. Printable worksheets and answers included throughout. Please review if you buy as any feedback is appreciated!
danwalker
Polygons introduction

Polygons introduction

A complete lesson on types of polygon, although it goes well beyond the basic classifications of regular and irregular. This lesson gives a flavour of how my resources have been upgraded since I started charging. Activities included: Starter: A nice kinesthetic puzzle, where pupils position two triangles to find as many different shapes as they can. Main: A slide of examples and non-examples of polygons, for pupils to consider before offering a definition of a polygon. A slide showing examples of different types of quadrilateral . Not the usual split of square, rectangle, etc, but concave, convex, equilateral, equiangular, regular, cyclic and simple. This may seem ‘hard’, but I think it is good to show pupils that even simple ideas can have interesting variations. A prompt for pupils to try and draw pentagons that fit these types, with some follow-up questions. A brief mention of star polygons (see my other resources for a complete lesson on this). Slides showing different irregular and regular polygons, together with some follow-up questions. Two Venn diagram activities, where pupils try to find polygons that fit different criteria. This could be extended with pupils creating their own Venn diagrams using criteria of their choice. Could make a nice display. Plenary: A table summarising the names of shapes they need to learn, with a prompt to make an educated guess of the names of 13, 14 and 15 sided shapes. Minimal printing needed and answers included where applicable. I have also added key questions and suggested extensions in the notes boxes. Please review if you buy as any feedback is very much appreciated.
danwalker
Coordinates rich task

Coordinates rich task

This started as a lesson on plotting coordinates in the 1st quadrant, but morphed into something much deeper and could be used with any class from year 7 to year 11. Pupils will need to know what scalene, isosceles and right-angled triangles are to access this lesson. The first 16 slides are examples of plotting coordinates that could be used to introduce this skill, or as questions to check pupils can do it, or skipped altogether. Then there’s a worksheet where pupils plot sets of three given points and have to identify the type of triangle. I’ve followed this up with a set of questions for pupils to answer, where they justify their answers. This offers an engaging task for pupils to do, whilst practicing the basic of plotting coordinates, but also sets up the next task well. The ‘main’ task involves a grid with two points plotted. Pupils are asked to plot a third point on the grid, so that the resulting triangle is right-angled. This has 9 possible solutions for pupils to try to find. Then a second variant of making an isosceles triangle using the same two points, with 5 solutions. These are real low floor high ceiling tasks, with the scope to look at constructions, circle theorems and trig ratios for older pupils. Younger pupils could simply try with 2 new points and get some useful practice of thinking about coordinates and triangle types, in an engaging way. I have included a page of suggested next steps and animated solutions that could be shown to pupils. Please review if you buy as any feedback is appreciated!
danwalker
WW2 Bearings

WW2 Bearings

Lesson based on saving London in the Blitz using bearings. Begins with a discussion about what the blitz was and how these planes navigated. Ends with an air raid siren as students have to race to calculate the bearing RAF planes from Manchester have to travel to London on to intercept them. Proved very popular with my Year 8 class!
charli135
Measuring angles with a protractor

Measuring angles with a protractor

A complete lesson on how to use a protractor properly. Includes lots of large, clear, animated examples that make this fiddly topic a lot easier to teach. Designed to come after pupils have been introduced to acute, obtuse and reflex angles and they can already estimate angles. Activities included: Starter: A nice set of problems where pupils have to judge whether given angles on a grid are acute, 90 degrees or obtuse. The angles are all very close or equal to 90 degrees, so pupils have to come up with a way (using the gridlines) to decide. Main: An extended set of examples, intended to be used as mini whiteboard questions, where an angle is shown and then a large protractor is animated, leaving pupils to read off the scale and write down the angle. The range of examples includes measuring all angle types using either the outer or inner scale. It also includes examples of subtle ‘problem’ questions like the answer being between two dashes on the protractor’s scale or the lines of the angle being too short to accurately read off the protractor’s scale. These are all animated to a high standard and should help pupils avoid developing any misconceptions about how to use a protractor. Three short worksheets of questions for pupils to consolidate. The first is simple angle measuring, with accurate answers provided. The second and third offer more practice but also offer a deeper purpose - see the cover image. Instructions for a game for pupils to play in pairs, basically drawing random lines to make an angle, both estimating the angle, then measuring to see who was closer. Plenary: A spot the mistake animated question to address misconceptions. As always, printable worksheets and answers included. Please do review if you buy, the feedback is appreciated!
danwalker
Fortnite Bearings Fun

Fortnite Bearings Fun

If you haven’t heard your students talking about Fortnite then where have you been? 45 million people play the shooter game Fortnite and I can’t stop the kids I teach from talking about it. This activity incorporates lots of different concepts: Ratios/Scales Bearings Speed, distance, time Pythagoras Area problem solving Edit and remove questions as you want. If you print at 100% the scale will be 1.5cm to 250m Otherwise you might have to give it a measure if you print to fit Also: The locations from the bearings are locations required for one of the challenges this season to get them even more engaged. Half my class have taken the work home to finish so they can gain in game rewards
tree1568
Angles in a triangle

Angles in a triangle

A complete lesson on the interior angle sum of a triangle. Activities included: Starter: Some simple recap questions on angles on a line, as this rule will used to ‘show’ why the interior angle sum for a triangle is 180. Main: A nice animation showing a smiley moving around the perimeter of a triangle, turning through the interior angles until it gets back to where it started. It completes a half turn and so demonstrates the rule. This is followed up by instructions for the more common method of pupils drawing a triangle, marking the corners, cutting them out and arranging them to form a straight line. This is also animated nicely. A few basic questions for pupils to try, a quick reminder of the meaning of scalene, isosceles and equilateral (I would do a lesson on triangle types before doing interior angle sum), then pupils do more basic calculations (two angles are directly given), but also have to identify what type of triangles they get. An extended set of examples and non-examples with trickier isosceles triangle questions, followed by two sets of questions. The first are standard questions with one angle and side facts given, the second where pupils discuss whether triangles are possible, based on the information given. A possible extension task is also described, that has a lot of scope for further exploration. Plenary A link to an online geogebra file (no software needed, just click on the hyperlink). This shows a triangle whose points can be moved dynamically, whilst showing the exact size of each angle and a nice graphic of the angles forming a straight line. I’ve listed some probing questions that could be used at this point, depending on the class. I’ve included key questions and ideas in the notes box. Optional, printable worksheets and answers included. Please do review if you buy as any feedback is helpful and appreciated!
danwalker
Vertically opposite angles

Vertically opposite angles

A complete lesson on vertically opposite angles. Does incorporate problems involving the angle sum of triangles and quadrilaterals too, to make it more challenging and varied (see cove image for an idea of some of the easier problems) Activities included: Starter: A set of basic questions to check if pupils know the rules for angles at a point, on a line, in a triangle and in a quadrilateral. Main: A prompt for pupils to reflect on known facts about angles at the intersection of two lines, naturally leading to a quick proof that vertically opposite angles are equal. Some subtle non-examples/discussion points to ensure pupils can correctly identify vertically opposite angles. Examples and a set of questions for pupils to consolidate. These start with questions like the cover image, then some slightly tougher problems involving isosceles triangles, and finally some tricky and surprising puzzles. A more investigatory task, a sort-of angle chase where pupils need to work out when the starting angle leads to an integer final angle. Printable worksheets and answers included. Please do review if you buy, as any feedback is helpful!
danwalker