Why do this problem?
It gives experience of using 3D coordinates, visualisation, and
using the distance formula in 3D, and formulae for the area of a
triangle.
Possible approach
A good diagram isessential. You might discuss and draw and label
the diagram as a class effort and then the students could
complete the calculatons independently.
Key questions
What are the coordinates of the vertices of the
tetrahedron?