Trigonometric Ratios – Unit Circle
One of the new topics of the reformed GCSE Mathematics (9-1) syllabus is trigonometric ratios: students need to memorise the trig ratios for 0˚, 30˚, 45˚, 60˚ and 90˚. At A-level, students tend to find it difficult to learn these ratios by heart and GCSE students are most likely to struggle even more with this.
The 'Unit Circle' shows the trig ratios (sine, cosine and tangent) in context and it has been my experience that students find it much easier to learn these ratios by heart using the unit circle rather than the traditional table used by most teachers. It takes a little bit of time to get used to the ‘Unit Circle’’ as most of us are so used to the table in conjunction with the graphs. However, once you have made the transition, your will see that the students will memorise the trig ratios very quickly. It works best if the ‘Unit Circle’ is used from the very start when the trigonometric ratios are being introduced.
This resource consists of 11 pages: a blank ‘Unit Circle’, a completed ‘Unit Circle’ in degrees (both in colour and black and white), a completed ‘Unit Circle’ in radians (both in colour and black and white), four examples on how to find the ratios, using the sine-line, cosine-line and tangent-line, and for GCSE students just the first quadrant blank, completed, in colour and in black and white.
For your convenience, the Word file is included and can be edited to meet the needs of your students.