Recently I wrote about the mathematics of cutting and folding paper and about the golden ratio, . Here’s a video that brings these two ideas together. We see how to create a golden rectangle (a rectangle for which the ratio of the sides is ) by folding a piece of paper. [via Anthony Brand’s maths…
Tag: geometry
Measuring an angle with a ruler
In the September 2008 issue of the College Mathematics Journal Travis Kowalski presents an neat way to measure an angle using a ruler. He attributes the discovery to a student of his, Tor Bertin. Given an acute angle (the technique can be modified for obtuse angles), measure off a distance on each ray. Then measure…
The eyeballing game
A friend of mine sent me a link to the Eyeballing Game, presumably because it looks mathematical. At a glance it does look like geometry, but really it is a test to see how well you can recognize when geometric images are correctly aligned. Here’s what the creator of the website (a woodworker) wrote: Some…
Flatland and other videos about dimension
Not long ago I watched the DVD of Flatland staring Martin Sheen as the voice of Arthur Square. The movie is based on Edwin Abbott Abbott’s 1884 book of the same title. Flatland is a story of polygons living in a two dimensional world and A. Square’s discovery of the third dimension. It is also…
David Richeson: Division by Zero 