Delineated is an oblique irregular tetrahedron of four right triangle faces where two vertices are formed by two right angle faces. The sum of the squares of the area ABO and ACO less the same of BCO equals that of ABC.
A2ABC = A2ABO + A2ACO – A2BCO
.25a2b2 = (.25a2(h2+b2)) + (.25b2 h2) – (.25c2h2)
0 = 25h2(a2+b2-c2)
c2 = a2+b2
