Find the surface area of a sphere of diameter:

(i) 14 cm

(ii) 21 cm

(iii) 3.5 m

(i) Radius (r) of sphere =

=

= 7 cm

Surface area of sphere = 4r²

= 4 * * 7 * 7

= 88 * 7

= 616 cm²

(ii) Radius (r) of sphere =

=

= 10.5 cm

Surface area of sphere = 4r²

= 4 * * 10.5 * 10.5

= 1386 cm²

(iii) Radius (r) of sphere =

=

= 1.75m

Surface area of sphere = 4r²

= 4 * * 1.75 * 1.75

= 38.5 cm²