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`)

Answer 1

(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.