743 Type 14: The Stein pentagon

- [Instructor] In this movie we'll take a look…at type 14 of the perfectly tessellating…irregular convex pentagons.…And to see what that looks like,…I'm gonna bring up the art boards panel…by going up to the window menu…and choosing the art boards command.…And that way I can easily switch between…a couple of art boards down here…near the bottom of the list.…So I'm gonna double click on type 14…in order to advance to this guy right here,…which was discovered by a German math student…named Rolf Stein back in 1985.…And as I hope you'll remember by now,…all the angles appear in bold right here, all five of them,…and the sides appear in italics.…

And so notice we have some pretty familiar rules.…A equals 90 degrees so we've got a right angle…at this location.…Two B plus C equals 360 degrees…whereas C plus E equals 180 degrees.…And if that does by any chance look familiar,…it's because those are the same angle rules…that we saw with type 11, which was created…by Marjorie Rice.…So the very same angle rules prevail.…Though, as we'll see, they're more specific…