Pythagorean Theorem

The Pythagorean Theorem is a theorem that the sum of the squares of the legs of any right
(90 degree) triangle is equal to the square of the hypotenuse.  What does this actually mean?
If you let the legs of the triangle be A and B, then let the side opposite the right angle in the triangle (called the hypotenuse) be C, then A2 + B2 = C2.  Observe the drawing.  

Text Box: C2


Text Box: B2 


Text Box: A2


Let A = 3 inches and let B = 4 inches.  Since A2 + B2 = C2, substituting the given values you would have 32 + 42 = C2 and 9 + 16 = C2.  Solving for C you would get 25 = C2, and C = 5 inches.  Note:  9 and 16 must be added together before the square root is applied.

General Algebra Tips

The views and opinions expressed in this page are strictly those of Mary Lou Baker.
The contents of this page have not been reviewed or approved by Columbia State Community College.

This page was edited on 15-Nov-2007