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5 votes
8 ft

10 ft
Find the area of this figure. Round your
answer to the nearest hundredth. Use
3.14 to approximate T.
A =[?] ft2

8 ft 10 ft Find the area of this figure. Round your answer to the nearest hundredth-example-1

1 Answer

5 votes

Answer:

105.12 ft²

Explanation:

You want the area of an 8 ft by 10 ft rectangle with a semicircle attached to one of the short sides.

Area

The area of the figure is equal to the sum of the areas of the rectangle and the semicircle.

Rectangle

The rectangle area is ...

A = LW

A = (10 ft)(8 ft) = 80 ft²

Semicircle

The area of the semicircle is ...

A = (1/2)πr²

A = (1/2)(3.14)(4 ft)² = (3.14)(8 ft²) = 25.12 ft²

Total

The total area is the sum of these:

A = 80 ft² +25.12 ft² = 105.12 ft²

The area of the figure is about 105.12 ft².

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Additional comment

A semicircle has the same area as a rectangle with long side equal to the diameter, and short side equal to (π/4) times the radius. This means the figure's area is equivalent to the rectangle formed by adding 4×(π/4) = π to the 10 ft length. This is the calculation shown in the attachment.

A = 1/2πr² = 1/2π(d/2)r = d(r·π/4) . . . . . area of the semicircle

When figures involve rounded or pointed shapes, we often find it convenient to use the appropriate scale factor to convert them to equivalent rectilinear shapes.

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8 ft 10 ft Find the area of this figure. Round your answer to the nearest hundredth-example-1
User Ken Zhang
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