Can’t believe this was the Bizarro cartoon for today. Off to Twitter Math Camp!

A real Treasure Trove! :) From total beginner to more advanced.

Wow! Simon Gregg got playing with the same 20-80-80 triangle as I did, but his results are a lot prettier! Read the post. Wonder at the marvels.

David Marain (@dmarain) shared an angle chasing puzzle in the 80-80-20 isosceles triangle. Quite a nice one.

I chased a bit, then modeled in GeoGebra. Then I made a tool for making an ASA triangle which was handy for making angle chasing problems. Then I generalized the problem, and found that the 80-80-20 triangle had lots of neat situations that other triangles do not. (Here it is on GGBTube)

Is there something that makes this triangle special?

P.S. Turns out Simon Gregg (@Simon_Gregg) was also intrigued by this, and made some great mathart along the way. Check out his post.

Opere di Eugenio Carmi.

Opere esposte a Spoleto (PG) Italy.

http://www.spoletoarte.it/art_Eugenio_Carmi.php (10 foto)

wonderful.

Two curves cut all circles at right angles: straight line and a tractrix.

I didn’t know what a tractrix was, so I Googled it! Tractrix definition from Wikipedia:

Tractrix(from the Latin verbtrahere”pull, drag”; plural:tractrices) is the curve along which an object moves, under the influence of friction, when pulled on a horizontal plane by a line segment attached to a tractor (pulling) point that moves at a right angle to the initial line between the object and the puller at an infinitesimal speed.Here’s a gif from Wikipedia showing a tractrix being created from dragging a pole:

Recent GGB Work.

Two recent GeoGebra sketches had too much writing to post here. The Mario Brothers was in response to a neat post from @approxnormal (blog, GGBTube), and the complex to complex polynomial sketch was in response to Numberphile’s recent & great video on the Fundamental Theorem of Algebra (blog, GGBTube).

{7,3} Tiling by

John Baezvia @amermathsoc

Heptagonal Hyperbolic. John blogs at Azimuth, might want to check it out. Lots of mathematical study of climate change.