Find the missing leg of a right triangle if one leg is 5 and the hypotenuse is 13

a^2 = 13^2-5^2 which is 144

then square root it and its 12

Use Pythagorean theorem (a squared is equal to c squared minus b squared)

Where a is the unknown leg, c is the hypotenuse and b is the known leg

a^2 = 13^2-5^2 which is 144

Then square root one hundred and fourty four to get rid of the power on a

Square root of one hundred and fourty four is twelve