Similar Shapes, Trigonometry, and Pythagoras Proofs

This pair of tasks interweaves similar and congruent triangles with finding perimeters, areas, angles using trigonometry and, finally, proving Pythagoras’ theorem.

Inspired by Teaching Together with Jonathan Hall (@StudyMaths) and Charlotte Hawthorne (@mrshawthorne7), I wanted to see how we could introduce proofs of Pythagoras to pupils without just telling them. Similar shapes gave the perfect opportunity!

Fully editable PPT with solutions below as always!