a2 + b2 = c2. the first leg of a right triangle squared + the second leg of the triangle squared = the hypotenuse squared.
good to know! memorizing the common ratios of sides in a pythagorean triple triangle can save you time on the act. here are the ones to know: (3,4,5), (5,12,13), (7, 24, 25), (8,15,17).