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Question
Find the area and perimeter of the following semicircles: Radius = 1.4cm
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Solution
The Area of a Semi-circle with radius r = `(pi"r"^2)/(2)`
the Perimeter of a Semi-circle with radius r
= πr + 2r
= r(π + 2)
= `"r"(22/7 + 2)`
= `(36)/(7) xx "r"`
The Area of a Semi-circle with radius 1.4cm
= `pi(1.4)^2/(2)`
= `(22)/(7) xx (1.4)^2/(2)`
= 3.08cm2
The Perimeter of a Semi-circle with radius r
= π(1.4) + 2 x 1.4
= 1.4(π + 2)
= `14(22/7 + 2)`
= `(36)/(7) xx 1.4`
= 7.2cm.
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