The Pythagorean Theorem states that in a right triangle ABC, the sum of the squares of the measures of the lengths of the legs, a and b, equals the square of the measure of the hypotenuse c, or a²+b²=c². Write a two-column proof to verify that a=√c²-b². Use the Square Root Property of Equality, which states that if a²=b², then a=±√b²