Question

The radius and height of a cylinder are in the ratio 7:2. If the volume of the cylinder is 8316cm³, find the surface area of cylinder.

Answer 1

Given that radius and height of a cylinder are in the ratio 7:2

Hence radius/height =7/2

r = (7/2) h

Therefore volume of the cylinder = πr²h

8316 = 22/7 × (7/2) h × (7/2) h × h

h³= 216

h = 6cm

Therefore r = 21cm

We know that total surface area of cylinder = 2πr(r + h)

Total surface area = 2 × 22/7 × 21 (21 + 6)

Total surface area = 3564 cm²