[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