Question

a surface area of a sphere is 616 cm² find the radius

Answer 1

Hi friend
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Your answer
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Surface area of a sphere = 616 cm²

Then,
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$4 \times \pi \times (r) {}^{2} = 616 \\ \\ = > 4 \times \frac{22}{7} \times r {}^{2} = 616 \\ \\ = > r {}^{2} = \frac{616 \times 7}{4 \times 22} \\ \\ = > r {}^{2} = 49 \\ \\ = > r = \sqrt{49} \\ \\ = > r = 7 \: cm$
Therefore,
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Radius of the sphere = 7 cm

HOPE IT HELPS

Answer 2

its simple
surface area of a sphere = 4 x pi x r^2 = 616cm^2
4 x 22/7 x r^2 = 616
r^2 = 616 x 7/22 x 4
r^2 = 154 x 7/22
r^2 = 14 x 7/2
r^2 = 7 x 7
r^2 = 7^2
r = 7cm