Why use this resource?
A review of work they have seen before (similar triangles and Pythagoras’ theorem) and a chance to consolidate and deepen understanding of these ideas. Working through the parts of this exercise will also remind students of important points about scale factors with length and area. Some parts do require some confidence with manipulating surds and could be a way of finding which students need extra practice.
If two triangles are similar, how are their perimeters related?
If two triangles are similar, how are their areas related? How can we tell whether a triangle is right-angled, isosceles, equilateral or scalene? Could it have two or more of those properties?