# Homework Help: Pythagorean theory help-

1. Nov 23, 2012

### christian0710

Hi
if i have a diagonal in a right triangle costing of 4x and let's say the two sides are a (same size).

Is it then correct to write (4r)2=2a2 or is it correct to write
4r2=2a2

If (4r)2=2a2 is correct, is it then correct to say 16r2=2a2 and √(2a2)/16)

2. Nov 23, 2012

### Mentallic

I'm really confused with what you're asking. Start again, and slowly, explain what the length of each side is.

3. Nov 23, 2012

### HallsofIvy

What does "consisting of 4x" mean?

Where did "r" come from? Is it what you called "x" before?

IF the length of the diagonal is 4r and the two sides have length a, then the Pythagorean theorem says that $(4r)^2= a^2+ a^2$ or $(4r)^2= 2a^2$.

Yes, $(4r)^2= 16r^2= 2a^2$. I don't know what that last expression is supposed to be but if $16a^2= 2a^2$ then $r^2= 2a^2/16= a^2/8$ and, taking square roots of both sides, $r= a/\sqrt{8}= a/(2\sqrt{2})= a\sqrt{2}/4$.