Pythagorean Theorem:

The Pythagorean Theorem is a tool which can be used to solve for unknown values on right triangles.  In sequence to use the Pythagorean Theorem, a term must be described. The term hypotenuse is used to describe the side of a right triangle opposite the right angle. A line segment C is the hypotenuse of the triangle in Figure.

Figure: Triangle

The Pythagorean Theorem states which in any right triangle, the square of the length of the hypotenuse equals the sum of the squares of the lengths of the other two sides.

This may be written as c² = a²+ b² or