Re: [math-fun] constant-width convex objects

On 1/12/13, Warren Smith <warren.wds@gmail.com> wrote:

1. The Minkowski sum of two constant-width convex objects, is another. Scaling and/or rotating one, yields another.

What appeared fiendishly involved in the special case M_V (+) M_F is immediately seen to be a one-liner when abstracted. Minkowski sum commutes with (ie. is invariant under) translation, so the diameter lines in both summands can be brought into coincidence; then the (1-space) mean width in that direction is the mean of the widths. QED & DUH! WFL