Question

Find the surface area of sphere of radius

Answer 1

it's very easy
like this
surface area of sphere =4py r squar
=4×22/7×(10.5×10.5
=1385.84
like this you can solve BandC

Answer 2

HI,
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a) Question :-Find the surface area of sphere of radius 10.5cm

a)Answer:- Given : Radius of 10.5cm 
 We know that, surface area of a sphere= 4$\pi$$r^{2}$

= ( 4 * $\frac{22}{7}$ * 10.5 *10.5)
∴Answer=1386$cm^{2}$

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b) Given r = 5.6cm
 We know that surface area of a sphere = 4$\pi$$r^{2}$
= [4 * $\frac{22}{7}$ * 5.6 * 5.6 ]
=394.24 $cm^{2}$
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c) Given r = 14cm
  We know that surface area of a sphere = 4$\pi$$r^{2}$
=[4 * $\frac{22}{7}$ * 14 * 14 ]
=2464 $cm^{2}$
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Hope you are helped :-)