Answer:
The volume of the tetrahedron is

Explanation:
To find the volume of a tetrahedron with vertices (2, 0, 0), (0, 4, 0), (0, 0, 4), (2, 4, 4).
We know by definition that the volume of a tetrahedron with vertices
is

From here we have:

Finding the determinant of that matrix we have:
=
