Using Trigonometry to Find Areas of Regular Polygons.

A set of tasks which lead the student through finding the height then area of an isosceles triangle, onto the areas of a variety of regular polygons and ultimately deriving a formula for this. Knowledge of right-angled triangle trigonometry required. It's a useful extension for this topic and requires good algebra manipulation skills. I have tried to remove the scaffolding as the tasks progress and have included opportunities for thinking about the connections between circles and regular polygons with large numbers of sides. Suitable as an extension activity for very able Year 9 or able GCSE students.