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Question
In the adjoining figure, the radius is 3.5 cm. Find:
(i) The area of the quarter of the circle correct to one decimal place.
(ii) The perimeter of the quarter of the circle correct to one decimal place. ( Take π = `22/7`)
Solution
(i) r = 3.5 cm = `7/2` cm ...(given)
Area of the quarter of the circle = `1/4` πr2
= `1/4 xx 22/7 xx (7/2)^2`
= `1/4 xx 22/7 xx (7/2 xx 7/2) `
= `77/8` cm2
= 9.625
= 9.6 cm2 ....(Correct to one decimal place)
(ii) Perimeter of the quarter of the circle
= `(2πr)/4 + r + r`
= `(πr)/2 + 2r`
= `1/2 xx 22/7 xx (3.5) cm + 2 xx (3.5)` cm
= ( 5.5 + 7 ) cm
= 12.5 cm.
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