Question

If the lateral surface area of a right circular cylindrical pillar is 264 sq-metres and volume is 924 cubic-metres. Find the length of radius of the base of the cylinder.

Answer 1

Let the radius of the base of the cylinder be r metres and height be h metres.
`:.` Its lateral surface `=2 pi r h ` sq-metres and volume `= pi r^(2)h` cubic-metres.
As per questions, ` 2 pi r h = 264`
or, `pi r h = 132 ` . . . . . . . (1)
and `pi r^(2) h = 924` or, `pi r h xx r = 924 ` or, `132 xx r = 924` by (1) or, `r= (924)/(132)=7`
Hence the required radius `=7` metres.