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 $0\le z\le h$, $x^2+y^2\le (z\tan \alpha {)}^2$, where $0<\alpha <\pi /2$ is the semi-angle. Its closed boundary includes both the lateral surface and the base Euclidean disk.