Determine the volume of the body obtained by cutting the ball of radius by the trihedron with vertex in the center of that ball, it its dihedral angles are
%V0
Determine the volume of the body obtained by cutting the ball of radius $R$ by the trihedron with vertex in the center of that ball, it its dihedral angles are $\alpha, \beta, \gamma.$
Izvor: Međunarodna matematička olimpijada, shortlist 1967
Školjka 
by the trihedron with vertex in the center of that ball, it its dihedral angles are 