Ed Southall (@edsouthall.bsky.social)さんのイラストまとめ

🎅 puzzle books for all ages and YBW 2nd edition for understanding why stuff works in maths :)
https://t.co/kvmmnahXAH

My newest book, Geometry Juniors is now available for preorder from The Mathematical Association. It will be in stock from next week & is aimed at 8-12 year olds 😀

You can order it here for £7 with membership or £10 w/o

👇
https://t.co/OG7gGEn4eR

3 unit circles constructed such that each passes through the centre of another as shown. What is the area of the pink shaded region?

Napoleon's Theorem : Equilateral △s on the sides of any △, all outward or all inward:

Lines connecting the centres form an equilateral △.

What's extra cool is that their area difference is the area of the original △ 🤩🤯

The pink dots are midpoints between black dots on the regular pentagon.
What is the pink angle?

What's the relationship between the pink angles?

What fraction of the square is shaded?

Created entirely with a hole punch. Pretty neat.