Mathematics
If the area of a circle is 78.5 cm2, find its circumference. (Take π = 3.14)
Mensuration
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Answer
By formula,
Area of circle = πr2
⇒ πr2 = 78.5
⇒ 3.14r2 = 78.5
⇒ r2 = = 25
⇒ r = = 5 cm.
Circumference = 2πr = 2 × 3.14 × 5 = 31.4 cm.
Hence, circumference = 31.4 cm.
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