Theorem 2 The area of the med,i,al parallelogram determi,ned by the edges oJ lengths d and e i'n the tetrahedron of Fi,gure 1 is ir/+a'"'* (b2 + f2 * az - c2)2 Proof:
Theorem 2 The area of the med,i,al parallelogram determi,ned by the edges oJlengths d and e i'n the tetrahedron of Fi,gure 1 isir/+a'"'* (b2 + f2 * az - c2)2Proof: