Krzysztof Dmowski @xaphanpl

**foldworks** @foldworks@mathstodon.xyz · 4d *

Multi-level Cairo tiling outside Deichman Library, Oslo, Norway: something strange going on between the medium and big hexagons?

“...opened to the public on 18 June 2020. Deichman Bjørvika has won several awards, including the International Federation of Library Associations and Institutions / Systematic Public Library of the Year award” https://en.wikipedia.org/wiki/Oslo_Public_Library

Edit: deleting and redrafting so that post is public, and should have been threaded with https://mathstodon.xyz/@foldworks/114500543669491352
#TilingTuesday #geometry #MathArt #photography #architecture #pentagon #hexagon #library

Photograph of grey street paving that consists of symmetrical pentagons in in symmetrical hexagons. The middle has medium-sized hexagons; the left has pentagons inside the hexagons; the right has bigger hexagons with pentagons inside.

**Iakov Davydov** @idavydov@mstdn.science · May 10 *

May 10 *

Iakov Davydov @idavydov@mstdn.science

I designed a bolt with a Reuleaux triangle shaft that turns inside a square nut.
It’s a strange bit of geometry that actually works—thanks to the constant-width shape.

https://www.printables.com/model/1278549-impossible-reuleaux-triangle-bolt-with-square-nut

GIF

3D Printerrd Impossible Reuleaux Triangle Bolt with Square Nut & Clicker Assembly: including end cap, ratchet wheel, clicking ring, retainer disc, square nut, round nut, and the bolt

GIF

#3DPrinting #ReuleauxTriangle #WeirdMechanisms

**Christian Guerrero** @Guerrero@pixelfed.social · May 6

May 6

Christian Guerrero @Guerrero@pixelfed.social

#architecture #modernism #design #structure #urban #geometry #minimalism #skyscraper #facade #perspective #innovation

#innovation

**foldworks** @foldworks@mathstodon.xyz · May 6

May 6

foldworks @foldworks@mathstodon.xyz

Shah-i-Zinda, Samarkand, Uzbekistan.

“The Shah-i-Zinda Ensemble includes mausoleums and other ritual buildings of 11th–15th and 19th centuries. ...meaning "The living king" … The Shah-i-Zinda complex was formed over eight (from the 11th until the 19th) centuries and now includes more than twenty buildings.” https://en.wikipedia.org/wiki/Shah-i-Zinda

Two sets of hexagonal tiles separated by a plain border.
The left set of tiles: interlaced white lines make hexagons and hexagrams containing yellow flowers. Red, blue and yellow polygons fill in the other areas. The hexagon tiles have a middle border of white, cyan and blue square and rectangle tiles making cross shapes.
The right set of tiles: the centre of each tile is a cyan hexagon surrounded by white equilateral triangles and blue kites.

#TilingTuesday #tiling #IslamicPattern

**Bibliolater** @bibliolater@qoto.org · May 2 *

May 2 *

Bibliolater @bibliolater@qoto.org

**Mathematics discovers that rose petals are found to contain a unique geometry**

“_Unlike the smooth contours of other flowers, the originally curved petals of roses end up forming polygons with straight edges_”

https://english.elpais.com/science-tech/2025-05-02/mathematics-discovers-that-rose-petals-are-found-to-contain-a-unique-geometry.html.

EL PAÍS English · May 2Mathematics discovers that rose petals are found to contain a unique geometryUnlike the smooth contours of other flowers, the originally curved petals of roses end up forming polygons with straight edges

#Geometry #Roses #Maths

Replied in thread

**foldworks** @foldworks@mathstodon.xyz · Apr 26

Apr 26

foldworks @foldworks@mathstodon.xyz

I tried to model these origami as transformation between cube and octahedron in Geogebra, but ended up with this instead
#MathArt #geometry #animation #loop #geogebra #tetrahedron #3d

GIF

Continued thread

**foldworks** @foldworks@mathstodon.xyz · Apr 25

Apr 25

foldworks @foldworks@mathstodon.xyz

Two modular origami cubes made from 1:√2 rectangles and squares (Canoe Unit 90° by me).
#origami @origami #MathArt #geometry #cube #ModularOrigami #papercraft #craft

Two origami cubes on a lilac background. Each is made from six units.
The cube on the right has two opposite vertices missing, as well as parts of the adjacent faces. The missing parts of the adjacent faces are larger on the cube on the left.
The colours of the left cube are red and white; the right cube is red and blue.

**foldworks** @foldworks@mathstodon.xyz · Apr 25 *

Apr 25 *

foldworks @foldworks@mathstodon.xyz

Three modular origami octahedra made from three different kinds of rectangles (Canoe Unit 60° by me).
From left to right, the rectangles are 1:√2, square and 2:√3.

#origami @origami #MathArt #geometry #octahedron #ModularOrigami #papercraft #craft

Three origami octahedra on a lilac background.
The octahedron on the right has a triangular window on the top. The window of the middle octahedron extends onto the adjacent faces by about a quarter. The octahedron on the left has open faces: the edges dominate.
From the left, the colours are blue and white, pink and purple and yellow and orange.

**Sean Alexander** @sean_alexander@pixelfed.social · Apr 20

Apr 20

Sean Alexander @sean_alexander@pixelfed.social

Street photography as geometric graphic design layout.

Denver, CO (2022)

#photography #streetphotography #geometry #graphicdesign #layout #abstract

#abstract

**Sonja P. Panuska** @froeki44@pixelfed.social · Apr 18

Apr 18

Sonja P. Panuska @froeki44@pixelfed.social

Pulling the lines
#farming #geometry #simplicity

#simplicity

**Chris Purcell** @ccppurcell@mathstodon.xyz · Apr 17

Apr 17

Chris Purcell @ccppurcell@mathstodon.xyz

Here's a stupid #geometry / #astronomy question. Planetary orbits are ellipses (under the obvious simplifying assumptions) which are conic sections. So what's the cone? There are infinitely many cones that fit of course. But is there one that best explains? To put it another way, is there a neat geometric argument that an orbit should be an ellipse, that doesn't require too much physics? #mathematics

Continued thread

**Jean-Baptiste Etienne** @JeanBaptisteEt4@mathstodon.xyz · Apr 16

Apr 16

Jean-Baptiste Etienne @JeanBaptisteEt4@mathstodon.xyz

A "big" one :

#geogebra : www.geogebra.org/m/tzmjrbqz
#truchet #mathart #geometry #symetries #reflexion

**foldworks** @foldworks@mathstodon.xyz · Apr 15

Apr 15

foldworks @foldworks@mathstodon.xyz

Patterned carpet, Loughborough University, England
#Tiling #TilingTuesday #Pattern #Geometry #MathArt #MathsArt

A black and grey carpet with interlocking Y-shaped motifs.

**Dani Laura (they/she/he)** @DaniLaura@mathstodon.xyz · Apr 15

Apr 15

Dani Laura (they/she/he) @DaniLaura@mathstodon.xyz

Tessellations with quarter of octagons and two sizes of squares.
#tilingtuesday #geometry #tiling

Tessellation in yellow, cyan and magenta, two axes of symmetry except for complete octagons (or considering just the colours).

Tessellation in yellow, cyan and magenta, two orthogonal axes of symmetry.

Tessellation in yellow, cyan and magenta, one axe of symmetry, changing from top to bottom.

**n-gons** @ngons@mathstodon.xyz · Apr 12

Apr 12

n-gons @ngons@mathstodon.xyz

Perfect fit.

GIF

#Hedron #Geometry #MathArt

**Bibliolater** @bibliolater@qoto.org · Apr 9

Apr 9

Bibliolater @bibliolater@qoto.org

**Descartes’ Mathematics**

“_In La Géométrie, Descartes details a groundbreaking program for geometrical problem-solving—what he refers to as a “geometrical calculus” (calcul géométrique)—that rests on a distinctive approach to the relationship between algebra and geometry._”

Domski, Mary, “Descartes’ Mathematics”, The Stanford Encyclopedia of Philosophy (Summer 2025 Edition), Edward N. Zalta & Uri Nodelman (eds.), forthcoming URL = <https://plato.stanford.edu/archives/sum2025/entries/descartes-mathematics/>.

#Descartes #History #HistSci