The total surface area of a hemisphere is 462 cm2. The diameter of this hemisphere is:

28 cm 21 cm 7 cm 14 cm

14 cm

We know that, Total surface area of a hemisphere = 3πr2 We have, The total surface area of a hemisphere = 462 3 πr2 = 462 = 3 × \(\frac{22}{7}\) × r2 = 462 = r2 = 462 × \(\frac{7}{22}\) × \(\frac{1}{3}\) = r = \(\sqrt {49}\) = 7 cm and the diameter = 7 × 2 = 14 cm