एक चतुष्फलक के चारो शीर्ष O(0,0,0), A(1,2,1),B(2,1,3) और C(-1,1,2) है चतुफलक का आयतन ज्ञात कीजिए।

A tetrahedron has vertices at O(0,0,0), A(1,2,1), B(2,1,3) and C(-1,1,2). Then the angle between the faces OAB and ABC will be

A tetrahedron has vertices O(0,0,0), A(1,2,1), B(2,1,3) and C(-1,1,2) . Then the angle between the faces OAB and ABC is

A tetrahedron has vertices O(0,0,0), A(1,2,1), B(2,1,3) and C(-1,1,2). Then the angle between the faces OAB and ABC is

A tetrahedron has vertices O (0,0,0), A(1,2,1,), B(2,1,3) and C(-1,1,2), the angle between faces OAB and ABC will be

A tetrahedron has vertices O(0,0,0),A(1,2,1),B(2,1,3),a n dC(-1,1,2), then angle between face OA B and A B C will be

If O(0, 0, 0), A(x, 1, -1), B(0, y, 2) and C(2, 3, z) are coplanar, then