a^2 + b^2 = c^2.....a and b are ur legs and c is ur hypotenuse
5^2 + b^2 = 10^2
25 + b^2 = 100
b^2 = 100 - 25
b^2 = 75...now take the square root of both sides...this gets rid of the ^2 on the left side.
b = sq rt 75
b = 8.66 <===measure of aq
*** the pythagorean theorem (a^2 + b^2 = c^2) can only be used on right triangles