TomD
"(Have you figured out yet that if there are four points in space (not all in the same plane) that there are FOUR ways to choose three of the four points to make four different planes?) "

Oh yeah, I design hulls in the CAD in my brain, and run the number up there also. 4 points is nothing. I'm spacial, just not necessarily able to communicate. I went to french schools, ever watch the french news vs the NA, or their talk shows. When I discovered how slowly people wanted to speak it took me a decade to slow down. People in my family tend to get mistaken for mathematicians, we only have the one with a PHD. I remember explaining to the most powerful CEO in the Canadian investment industry how all the MBAs in his office had queered the capital calcs for the period post bank takeovers - pretty much the most important deal of their lives. But I am basically a numbers guy I never took any math beyond high school, and that was a moving shipwreck.