The radius of a cylinder is 2 r units and height is 3 r units. Find the curved surface? Select the correct option:
A) 18 πr2 B) 12πr2 C) 3 πr2 D) 6 πr2 E) 9 πr2
Explanation:   2 * π * 2r * 3r = 12πr2   Answer: 12πr2
<result>B</result>
The radius of a cylinder is 2 r units and height is 3 r units. Find the curved surface?