Monday, July 13, 2020

Dihedral Group

(Click on the comic if you can't see the full image.)

(C)Copyright 2020, C. Burke. "AnthroNumerics" is a trademark of Christopher J. Burke and (x, why?)

Reuse a gag? I'll even put them in Order for you.

I was going to wait until next week to post this, but I couldn't wait. (Plus, it was quick for posting.) There will be something on Twitter in a few days.

A dihedral group is the group of rotational and reflectional symmetries of a regular polygon. If the polygon has 12 sides, as the dodecagon in the comic, then it has 12 rotational symmetries, because you can map it onto itself with every 15 degree rotation, and 12 reflectional symmetries, one for each of the rotations, plus the original. This gives it a total of 24.

In general, for any n-gon, the order number will be 2n.

And, of course, since January, the store now has a screen, and everyone is wearing masks.

Come back often for more funny math and geeky comics.

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