A hollow garden roller 63 cm wide with a girth of 440 cm is made of iron 4 cm thick. The volume of iron used is?

∵ Circumference of the girth = 440 cm
⇒ 2πr = 440
⇒ r = 440 / (2 x 7/22) = 70 cm
Thus, Outer radius = 70 cm
Inner radius = (70 - 4) cm = 66 cm
Volume of iron = π[(70)² - (66)²] x 63 cm³
= (22/7) x 136 x 4 x 63 cm³
= 107712 cm ³