Right circular cone
= Right circular cone
A right circular cone has an axis through its apex and the centre of its circular base. With the axis chosen as the $z$ axis, its solid interior is $0\leq z\leq h$, $x^2+y^2\leq(z\tan\alpha)^2$, where $0<\alpha<\pi/2$ is the semi-angle. Its closed boundary includes both the lateral surface and the base <Euclidean disk>.