A 4" by 6" by 8" rectangular solid is cut by slicing through the midpoint of three adjacent edges. What is the number of inches in the sum of the lengths of the edges of the tetrahedron that is cut?
Hectictar gave a great answer to this only yesterday so go find it!
Hint - half the lengths of the sides are 3,4 and 2
you must find the hypotenuses of these right angled triangles.