Find the surface area of a sphere of radius 10.5 cm.
Given,
Radius of sphere (r) = 10.5 cm
By formula,
Surface area of the sphere (A) = 4πr2
Substituting values we get :
A=4×227×(10.5)2=4×227×10.5×10.5=4×22×1.5×10.5=1386 cm2.A = 4 \times \dfrac{22}{7} \times (10.5)^2 \\[1em] = 4 \times \dfrac{22}{7} \times 10.5 \times 10.5 \\[1em] = 4 \times 22 \times 1.5 \times 10.5 \\[1em] = 1386 \text{ cm}^2.A=4×722×(10.5)2=4×722×10.5×10.5=4×22×1.5×10.5=1386 cm2.
Hence, surface area of the sphere = 1386 cm2.
