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The perimeter of a semicircle is 5.14 kilometres. What is the semicircle's area? Use 3.14 for ​pi

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4.3 kilometres

1. Find the diameter by using the formula of the perimeter of the semicircle:

P=1/2 pi d(diameter)

5.14=1/2×3.14×d

5.14=1.57d [divide all sides by 1.57]

1.57. 1.57d

rounded off it gives you the diameter as 3.3

2. Then find the area using the formula

A=1/2 pi r²

=1/2×3.14×1.65(half of 1.57)×1.65

this gives you the answer as 4.3 kilometres rounded off

Hope this is understandable

User Wachichornia
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