A cylinder has a side area of 942 square centimeters and a volume of 2355 cubic centimeters. How many centimeters is its bottom radius?

A cylinder has a side area of 942 square centimeters and a volume of 2355 cubic centimeters. How many centimeters is its bottom radius?


Idea: suppose that the radius of the bottom surface is r cm, then the side area is 2 × 3.14 × R × H = 942, that is, 3.14 × R × H = 942 / 2 ①, and the volume is 3.14 × R × R × H = 2355 ②; divide ② by ① to get r = 2355 / (942 / 2) = 5 (CM)
2355 ^ (942 ^ 2) = 5 (CM)