# Math Help - Leg squared theorem

1. ## Leg squared theorem

I took notes in class on this theorem, but still don't understand how to do it. Can someone explain how this works/what to do?

2. ## Re: Leg squared theorem

Originally Posted by jgolden1
I took notes in class on this theorem, but still don't understand how to do it. Can someone explain how this works/what to do?
What you have are three similar right triangles. The tedious part is figuring the correct correspondences.
Here is one $\Delta ACB \simeq \Delta ADC$ .
Can you find two more?
Then read off the corresponding proportionals and cross multiply.

3. ## Re: Leg squared theorem

You can prove $h^2=xy$ by using pythagoras' theorem for the big triangle and the two smaller triangles.
and you can prove that $a^2=yc$ and $b^2=xc$ by using $h^2=xy$ and pythagoras' theorem for the smaller triangles