geometry
posted by Misty .
Triangle ABC is a right triangle such that m angle B= 90 degrees. If AC= 12 and BC=9, what is the perimeter of triangle ABC ? round to the nearest tenth.

Use the Pythagorean theorem.
(AB)^2 + (BC)^2 = (AC)^2
Insert the values in the equation above and solve for AB, then add the values for each side to get the perimeter.