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प्रश्न
The area of a circle is 38.5 cm2. The circumference of the circle is
पर्याय
6.2 cm
12.1 cm
11 cm
22 cm
उत्तर
22 cm
Let the radius be r cm.
We know:
Area of a circle
= πr2 cm2
Thus, we have
πr2 = 38.5
`=>22/7xx"r"^2 = 38.5`
`⇒ r^2 = (38.5xx7/22)`
`=> "r"^2 = (385/10xx7/22)`
`=> "r"^2 = 49/4`
`=> r = 7/2`
Now,
Circumference of the circle = 2πr
`= 2 × 22/7xx"r"`
`=(2xx22/7xx7/2)`
= 22 cm
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