A Squared Plus B Squared Equals C Squared

Josh spent last week making a Recycle sign for HSM. He called me on Friday afternoon to find out how long the sides of the triangle need to be for the height to be six feet.

I said, "Don't ever let anyone say that you don't need math in real life!"
I did some calculations and found the answer...

And then I took a picture of the white board, to prove that though I was an English major, my one semester spent as a Math major was not in vain.