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Whats the surface area?

Whats the surface area?-example-1

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Answer:

1108 in²

Explanation:

You want the total surface area of the pentagonal prism shown.

Base area

The area of each of the two pentagonal bases is the sum of the area of the yellow rectangle and the area of the triangle above it. That sum is ...

A = LW +1/2bh

A = 5(12) +1/2(12)(9) = 12(5 +9/2) = 114 . . . . square inches

Lateral area

The lateral area of the prism is the sum of the areas of the 5 rectangles. That sum will be the product of the perimeter of the pentagonal base and the distance between bases.

LA = (12 +5 +11 +11 +5)(20) = (44)(20) = 880 . . . . square inches

Total area

The total surface area of the figure is the sum of the two base areas and the lateral area:

SA = 2(114 in²) +880 in² = 1108 in²

The surface area of the composite figure is 1108 in².

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Whats the surface area?-example-1
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