Question

A solid has a circular base of radius 3. If every plane cross section perpendicular the the x-axis is an equilateral triangle, then the volume is
a) 36
b) 12 sqr3
c) 18 sqr3
d) 24 sqr3
e) 36 sqr3

Answer 1

We can use \[\Large V = \int_{a}^{b} A(x) dx \]

Answer 2

is A(x)= (pi)r^2*(1/2)(pi)r^2

Answer 3

If we look at the an eagle eye view of the shape
we have