# Spinning a Circle, along a Circle!

Geometry Level 4

Consider a circle of variable radius which is displaced in such a way that one of the points of its circumference remains fixed on the $$x$$-axis and its centre moves along the circle $$x^2+ y^2 = 4$$. Also, the plane containing this circle is perpendicular to the $$x$$-axis.

Find the closed form of the volume of this solid.