9514 1404 393
Answer:
920 square feet
Step-by-step explanation:
The surface area is the sum of the areas of the different surfaces of the solid. This solid has 5 surfaces: 2 triangular bases and 3 rectangular faces.
The area of a triangle is given by the formula ...
A = 1/2·bh . . . . . where b is the base of the triangle, and h is its height
The dimensions shown on the "front" of the figure tell you the triangle has a base of 15 ft and a height of 8 ft. Its area is ...
A = (1/2)(15 ft)(8 ft) = 60 ft²
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The rectangular faces all have a width of 20 ft. So, the sum of their rectangular areas will be that width multiplied by the sum of their lengths. We call this the "lateral area" of the prism.
lateral area = (base perimeter) × (prism width)
= (8 ft + 15 ft + 17 ft) × (20 ft) = 800 ft²
The sum of the areas of the two base triangles and the lateral area is the total surface area of the figure:
total area = 2×60 ft² + 800 ft²
total area = 920 ft²
