Equilateral triangle revolution
Calculus
Level
4
An equilateral triangle of radius \( r\) in the first quadrant, one of whose sides lies on the \(x\)-axis, is revolved around the line \( y= -r.\) The volume of the resulting solid is \(c\pi r^3,\) for some real number \( c.\) What is \( c\)?
by
Patrick Corn