What you can do, is say the whole thing was a triangle, with 6 (3+3) being the hypotenuse and x being one of the legs.
You know that it's a right triangle, and you also know that the legs are the same length because of SAS.
So you can use the pythagorean's theorem here.
Since a = x and b is also equal to x, (because the sides are the same lengths)
x^2 + x^2 = 6^2
x^2 + x^2 = 36
2x^2 = 36
x^2 = 18
x = [tex] \sqrt{18} [/tex]
[tex] \sqrt{18} [/tex] = [tex] \sqrt{9} * \sqrt{2} [/tex]
x = 3[tex] \sqrt{2} [/tex]
Hope this helped :)
