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Question
A sprinkler placed at the centre of a flower garden sprays water covering a circular area. If the area watered is 1386 cm2, find its radius and diameter
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Solution
Area of the Circle = πr2 sq.units
Area of the circular portion watered = 1386 cm2
πr2 = 1386
`22/7 xx "r"^2` = 1386
r2 = `1386 xx 7/22`
= 63 × 7
= 9 × 7 × 7
r2 = 32 × 72
r = 3 × 7
Radius (r) = 21 cm
Diameter (d) = 2r = 2 × 21 cm
Diameter (d) = 42 cm
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