Below are three regular squares lined up next to each other. Square B is a fixed shape.

1. Using the points I and B, rotate and adjust squares A and C until points H and J meet to make a triangle. What is the size of the angle?
2. Now using the sliders, adjust the lengths of the sides for squares A and C and create a triangle as you did in part 1. What is the size of the angle now?
3. Given that square B has fixed lengths of sides equalling 4, what lengths of sides are needed for square A and square C in order to create a right-angled triangle? Is there a relationship between the three squares? Have a go!