Circle Theorems Code Breaker GCSE Higher

A Code Breaker puzzle on circle theorems. Thirteen circles, drawn to the true angles, each ask for the size of angle x. Students look their answer up in the Code Box, write down the letter it unlocks, then unscramble all thirteen letters to find something decorated in December.

The tiles cover all seven theorems: the angle at the centre, the angle in a semicircle, angles in the same segment, cyclic quadrilaterals, the tangent and the radius, the alternate segment theorem and chords. Some need two steps, such as a tangent then an isosceles triangle. The Code Box includes the answers that common slips give, such as halving an angle that should be doubled, so a wrong answer unlocks a letter that will not fit the word.

Answers are included as a separate file. One puzzle per A4.

Suitable for GCSE Higher (AQA G10) classes working on circle theorems.

AI was used to help create this resource, working from my own lesson design.