Find the surface area of a sphere of diameter | vedclass

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(A) Given,diameter of the sphere $d = 21 \, cm$.Radius $(r) = \frac{d}{2} = \frac{21}{2} \, cm = 10.5 \, cm$.The surface area of a sphere is given by

Vedclass · Accepted Answer

$1386$

Vedclass · Answer

(A) Given,diameter of the sphere $d = 21 \, cm$.Radius $(r) = \frac{d}{2} = \frac{21}{2} \, cm = 10.5 \, cm$.The surface area of a sphere is given by the formula $4 \pi r^{2}$.Substituting the values: $	ext{Surface Area} = 4 	imes \frac{22}{7} 	imes (10.5)^{2} \, cm^{2}$.$= 4 	imes \frac{22}{7} 	imes 10.5 	imes 10.5 \, cm^{2}$.$= 4 	imes \frac{22}{7} 	imes \frac{21}{2} 	imes \frac{21}{2} \, cm^{2}$.$= 22 	imes 3 	imes 21 \, cm^{2} = 1386 \, cm^{2}$.Thus,the surface area of the sphere is $1386 \, cm^{2}$.

Find the surface area of a sphere of diameter $21 \, cm$. Assume $\pi = \frac{22}{7}$. (in $, cm^{2}$)

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