Mark (✓) against the correct answer in each of the following:
The radius of a sphere is 21 cm. What is the surface area of the sphere?
(a) 9702 cm²
(b) 5544 cm²
(c) 12932 cm²
(d) 4312 cm²

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Solution
(b) 5544 cm²

$Surface area of sphere = 4 π r^{2} = 4 \times \frac{22}{7} \times 21 \times 21 = 5544 {cm}^{2}$

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Mark (✓) against the correct answer in each of the following: The radius of a sphere is 21 cm. What is the surface area of the sphere? (a) 9702 cm2 (b) 5544 cm2 (c) 12932 cm2 (d) 4312 cm2

(b) 5544 cm2 Surface area of sphere=4πr2=4×227×21×21=5544 cm2

Mark (✓) against the correct answer in each of the following:
The radius of a sphere is 21 cm. What is the surface area of the sphere?
(a) 9702 cm²
(b) 5544 cm²
(c) 12932 cm²
(d) 4312 cm²

(b) 5544 cm²

$Surface area of sphere = 4 π r^{2} = 4 \times \frac{22}{7} \times 21 \times 21 = 5544 {cm}^{2}$