The Pythagorean theorem says that if you have a right-angle triangle,
the square of the hypotenuse (that's the
side opposite the right angle) equals the sum of the squares of the
other two sides.
Using this triangle as an example, the hypotenuse
is side c.We have a = 3, and
b = 4. So:
c2 = 32 +
c2 = 9 + 16
c2 = 25
To find the length of c, all we do is take the square root of both
sides. In this case, c = 5.