Given is a trihedral angle OABC with a vertex O and a point P in its interior. Let V be the volume of a parallelepiped with two vertices at points O and P, whose three edges are contained in the rays OA, OB, OC. Calculate the minimum volume of a tetrahedron whose three faces are contained in the faces of the trihedral angle OABC and the fourth face contains the point P. geometry3D geometrytetrahedronVolumegeometric inequality