Definition:Right Circular Cone/Generating Angle

Definition

 * RightCircularCone.png

Let $K$ be a right circular cone.

Let point $A$ be the apex of $K$.

Let $O$ be the center of the base of $K$.

Let $B$ be the endpoint of a diameter of the base of $K$.

Then the angle $\angle OAB$ is the generating angle of $K$.