What is the surface area of the triangular prism? A triangular prism. The rectangular sides are 20 feet by 3 feet, 20 feet by 4 feet, and 20 feet by 5 feet.

252 ft²

Step-by-step explanation:

A triangular prism has three rectangles and two triangles, to find the surface area, first find the surface area of thee rectangles and then the surface area of the triangles. After that add all the surface area.

For rectangle 1, surface area = 20 * 3 = 60 ft²

For rectangle 2, surface area = 20 * 4 = 80 ft²

For rectangle 3, surface area = 20 * 5 = 100 ft²

The triangle has height, base and hypotenuse. 5 ft is the hypotenuse and the height and base are 3 ft and 4 ft.

5² = 3² + 4²

For the triangle, the surface area = 1/2 * base * height = 1/2 * 3 * 4 = 6 ft²

Total surface are = 60 + 80 + 100 + 2 (6) = 252 ft²