Solid of revolution

In engineering, manufacturing, and mathematics; a "solid of revolution" is some object which can be visualized by graphinging a function, and then rotating that graph around some axis, an "axis of revolution", so as to create a three-dimensional object.

A "surface of revolution" can be created by rotating an edge around an axis; such an area is equal to 2π ∫ (x) [√ (1 + [f ' (x)]²)] (dx). The quantity, [√ (1 + [f ' (x)]²)], comes from the arc-length formula.