#MathArtChallenge Day 67: Circular Celtic Grid

The challenge: To create this circular grid and then design using it.

Materials needed: Compass OR Desmos geometry.

Instructions are here: https://design.tutsplus.com/tutorials/geometric-design-a-celtic-grid–cms-24560

If you don’t have a compass, you could print out this pdf from my Desmos geometry construction:

#MathArtChallenge Day 66: Venn Diagrams

The challenge: Create a complete (all 16 spaces) 4 set venn diagram.

Materials needed: Pencil, paper

Then, follow this to see some pretty spectacular math.

#MathArtChallenge Day 65: Penrose Triangle

The Challenge: Create a penrose triangle.

Materials needed: Pencil, paper, etc.

#MathArtChallenge Day 64: Anamorphic Raintangle (from woollythoughts.com)

The challenge: Create a rainbow and get it reflected in a curved surface to reveal a rectangle. All credit here to Woolly Thoughts! (They have wonderful things for you to play with there.)

Materials needed: I crocheted mine, which was a fun puzzle to get an even rainbow. They have knitting instructions on their website, but you could just as easily draw this with markers. I used tinfoil as my reflective surface wrapped around a nail polish remover bottle. I bet you all get more creative than myself.

#MathArtChallenge Day 62: Wobblers

The Challenge: Build yourself a wobbler. Wobblers are 2 circle (or 2 ellipse!) constructions that have a constant center of mass. Or rather, a center of mass that doesn’t move up and down as the wobbler rolls. Thus, resulting in a satisfyingly continuous “wobble”.

Materials Needed: cardboard, ruler, boxcutter or scissors

I first heard about this from Matt Parker’s “Things to Make and Do in the 4th Dimension”, (which is an excellent read for anyone interested, and the link above even has some printable templates for both a circular and an elliptical wobbler) – he attributes this to A.T Stewart in 1966.


To build, cut out 2 congruent circles from cardboard (or something cardboard like).

Then cut a slit that is ~29.3% the length of the radius in each circle, and use that to connect.

Momath has a lovely large wobbler here. 

This website also has a lovely tutorial on making a wobbler from 2 CDs. 

#MathArtChallenge Day 61: Hilbert Curve

The challenge: Create a Hilbert curve.

Materials needed: Paper and pencil. Grid paper is helpful.

And here’s a neat extension from Vincent Panteloni: