Bill, I didn't see at all how the animated picture illustrated your post. It would be much more clear if you could present a fixed picture of the parallelogram with a line bisecting it into the two triangles, and a picture of a parallelogram with a line indicating the triangle to be chopped off. -- Gene From: Bill Gosper <billgosper@gmail.com> To: math-fun@mailman.xmission.com Sent: Sunday, February 14, 2016 1:33 PM Subject: [math-fun] A=bh/2 Remember when they taught you that the area of a triangle is half the area of the parallelogram you get by gluing two copies together? And the area of the parallelogram is the area of the rectangle you get by chopping a triangle off one end and gluing it on the other? Did anybody complain that this doesn't work for sufficiently skewed parallelograms? Fix: gosper.org/A=f(bh).gif --rwg _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun