Given vertices of regular tetrahedron OABC, prove that vector OA + OB + OC is perpendicular to plane ABC...
I've been racking my brain on this one, can't figure it out... would appreciate some help
I thought I'd center it on the origin:
(0, 0, 0)
(1, 0, 0)
(0, 1, 0)
(0, 0, 1)
A + B...