Carnival of Mathematics 225
Welcome to the Two-Hundred and Twenty-Fifth Carnival of Mathematics. Let’s start with facts about 225: Octagonal numbers are always fun: And then we can always think in gradians for a hexadecagon where the outside angles shown are 225 gradians (202.5 degrees or 1.125π radians). (Thanks David JONES f
Welcome to the Two-Hundred and Twenty-Fifth Carnival of Mathematics.
Let’s start with facts about 225:
- 225 = 152
- 225 = (1 + 2 + 3 + 4 + 5)2
- 225 = 13 + 23 + 33 + 43 + 53
- 225 is a highly composite odd number
- 225 is the smallest number that is a polygonal number in five different ways.
- 225 is a refactorable number.
Octagonal numbers are always fun:
And then we can always think in gradians for a hexadecagon where the outside angles shown are 225 gradians (202.5 degrees or 1.125π radians). (Thanks David JONES for the suggestion).
Submissions, news, and blogs:
- Oh happy day when Bartosz Ciechanowski posts something new, and it’s …drumroll… and airfoil! This article is delightfully interactive, demonstrates difficult to understand concepts, and makes complicated maths and simulations look beautiful and simple – Bravo! As someone who’s built many wind tunnels in STEM classes – I am grateful for the thoughtful and engaging content. (Thanks to Katie Steckles for the submission).
- Josh Silverman posted an elegant solution to the February Jane Street puzzle.
- I am super excited for The Coding Train’s challenge #181 — Weighted Voronoi Stippling it is a combination of beautiful maths and p5js!
- Juan Carlos Ponce Campuzano is celebrating 5 years of his Complex Analysis book (free, online, and beautiful).
- The podcast Infinitely Irrational has posted the first of three episodes on Cantor and infinity. This is a podcast that explores famous and not so famous mathematicians.
- Karen Campe shared this nature article on how decimals are 150 years older than we may have thought – wow!
- Karen also has a new blog post for a March Calendar Problems.
- John Golden has posted a fun game on his blog with linear equations.
- Sarah Carter has a new puzzle posted on her blog.
- Suzza wrote wonderful Valentine for Mathematics.
- The DiffGeom blog has a post on torus knots and how they apply them in making jewelry.
- John D. Cook submitted a post on the unit circle.
- Erkal shared a fun toy made from a Martin Gardner Puzzle.
- Kamil has a post on a functor.network about topology.
Numberphile has a new video:
Mastodon Posts:
- A post on 30 by John Carlos Baez and another one on pendulums.
- A lovely ellipse chalkboard drawing
- Non-euclidean Dreamer has beautiful art
- Rémi Eismann posts on favorite sequences
Submitted Twitter posts:
- Kit Yates posted on leap days
- A beautiful fractal in the boundaries involving neural networks
- A. Carpenter has been wowing with geometric beauty as usual.
- Libo Valencia posted a fun lego distributive property image