A circle touches the lines OA, OB and AB where OA and OB are
perpendicular. Show that the diameter of the circle is equal to the
perimeter of the triangle
A 1 metre cube has one face on the ground and one face against a
wall. A 4 metre ladder leans against the wall and just touches the
cube. How high is the top of the ladder above the ground?
The area of a regular pentagon looks about twice as a big as the pentangle star drawn within it. Is it?
Prove that the resulting triangle is an enlargement of the original triangle.
What is the scale factor of enlargement of the resulting triangle?
Use what you have discovered about the side lengths of the resulting triangle to come up with a proof of Pythagoras' Theorem.