Geometric composition involving equilateral triangles
IXOHOXI Magic Square
The neat magic square featured on this stamp was created by Brazilian mathematician Inder Taneja. This square, called IXOHOXI magic square, not only shows common properties like other magic squares, as well as being pandiagonal, but also include extra properties such as symmetries, rotations and reflections.
Shortest Path on a Cube
The regular hexagon hidden in a cube unfolds to a straight line on a net of the cube.
The Paradox of Infinity
पूर्णस्य पूर्णमादाय पूर्णमेवावशिष्यते ॥
“Removing infinity from infinity, leaves infinity”
– Brihadaranyaka Upanishad
Magic Inscribed Lotus
Indian mathematician Nārāyaṇa (1356) is the originator of the “Inscribed Lotus” (Padma Vrtta, a magic diagram constructed with the numbers of the 12×4 magic rectangle), in which every group of 12 numbers has the same sum 294.
A Paradoxical Zero-Length Hypotenuse
A strange right-triangle involving the unit imaginary number i
Sacred Geometry
Repeated barycentric subdivision results in a gorgeous fractal-ish pattern.
Impossible Structure
Perpetual Escher’s waterfall
Toeplitz’ Conjecture
Does every simple closed curve in the plane contain the vertices of a square?
No one knows, but the answer to this question is positive if the curve is sufficiently regular.
Four Constants in Four 4’s
The infamous problem of representing numbers with four 4’s appeared for the first time in 1881 in a London science journal. In 2001, a team of mathematicians from Harvey Mudd College found that we can even get four 4’s to approximate four notable constants: the number e, π, acceleration of gravity, and Avogadro’s number.
