Question

The base of a triangular prism is a right triangle with a base of 5 inches, a height of 12 inches, and a third side length of 13 inches. The height of the prism is 21 inches. Find the surface area of the prism.

Answer 1

690 sq in

Explanation:

SA = LA + 2B where LA is the lateral area and B is the area of the base

The triangular base has an area of

B = 1/2bh 1/2(5)(12) = 30

LA = ph where p is the perimeter of the base and h is the height of the prism

LA = (12 + 5 + 13)(21) = 30(21) = 630

SA = 630 + 2(30) = 630 + 60 = 690 sq in