Icosahedron

How to Construct an Icosahedron

How the greeks constructed the icosahedron. Source: Euclids Elements Book 13, Proposition 16. In geometry, a regular icosahedron is a convex polyhedron with 20 faces, 30 edges and 12 vertices. It is one of the five Platonic solids, and the one with the most faces. https://www.etsy.com/lis

From playlist Platonic Solids

How to Construct a Dodecahedron

How the greeks constructed the Dodecahedron. Euclids Elements Book 13, Proposition 17. In geometry, a dodecahedron is any polyhedron with twelve flat faces. The most familiar dodecahedron is the regular dodecahedron with regular pentagons as faces, which is a Platonic solid. A regular dode

From playlist Platonic Solids

Geodesic domes and spheres

Geodesic domes: http://shpws.me/qrM2 Geodesic spheres: http://shpws.me/qrM3

From playlist 3D printing

The Music of the Icosahedron – Hilarie Orman

From playlist G4G11 Videos

Regular polyhedra

This shows a 3d print of a mathematical sculpture I produced using shapeways.com. This model is available at http://shpws.me/q0PF.

From playlist 3D printing

The remarkable Platonic solids II: symmetry | Universal Hyperbolic Geometry 48 | NJ Wildberger

We look at the symmetries of the Platonic solids, starting here with rigid motions, which are essentially rotations about fixed axes. We use the normalization of angle whereby one full turn has the value one, and also connect the number of rigid motions with the number of directed edges.

From playlist Universal Hyperbolic Geometry

What are four types of polygons

👉 Learn about polygons and how to classify them. A polygon is a plane shape bounded by a finite chain of straight lines. A polygon can be concave or convex and it can also be regular or irregular. A concave polygon is a polygon in which at least one of its interior angles is greater than 1

From playlist Classify Polygons

Group theory 27: The icosahedral group

This lecture is part of an online math course on group theory. The lecture is about a few examples of groups, in particular the icosahedral group. In it we see that the icosahedral group is the only simple group of order 60, and show that all larger alternating groups are simple.

From playlist Group theory

Seminar: Five-fold symmetry, Schiffler points and the twisted icosahedron

This is a seminar talk given at UNSW in the School of Mathematics and Statistics. It discusses joint work with Dr. Nguyen Le of San Francisco State University on a combination of projective geometry and triangle geometry, figuring five fold symmetry, dihedral orderings, a lovely distance r

From playlist MathSeminars

Math Mornings at Yale: Asher Auel - Wallpaper, Platonic Solids, and Symmetry

The Platonic solids-the tetrahedron, cube, octahedron, dodecahedron, and icosahedron-are some of the most beautiful and symmetric geometrical objects in 3-dimensional space. Their mysteries started to be unraveled by the ancient Greeks and still fascinate us today. In 1872, the German geom

From playlist Math Mornings at Yale

Further adventures in stereographic projection

These stereographic projection models are available from my Shapeways shop: https://www.shapeways.com/shops/henryseg?section=Stereographic+Projection The torch/flashlight is a Mini Maglite AAA LED flashlight (http://maglite.com/shop/mini-maglite-led-2-cell-aaa-flashlight.html).

From playlist 3D printing

Competitive nucleation in nanoparticle clusters by Richard Bowles

Conference and School on Nucleation Aggregation and Growth URL: https://www.icts.res.in/program/NAG2010 DATES: Monday 26 July, 2010 - Friday 06 Aug, 2010 VENUE : Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru DESCRIPTION: Venue: Jawaharlal Nehru Centre for Advance

From playlist Conference and School on Nucleation Aggregation and Growth

Michael Tanoff - Son of O'Gara - G4G12 April 2016

Mathematical philately over the past half century

From playlist G4G12 Videos

32 and Truncated Icosahedron - Numberphile

The 32-sided truncated icosahedron forms the basis of many footballs (soccer balls!). It's also a big deal in chemistry. More links & stuff in full description below ↓↓↓ sixtysymbols video on footballs: http://www.youtube.com/watch?v=55M1cq62m2c periodicvideos video on buckyballs: http://

From playlist Football (soccer) on Numberphile

What is the difference between convex and concave

👉 Learn about polygons and how to classify them. A polygon is a plane shape bounded by a finite chain of straight lines. A polygon can be concave or convex and it can also be regular or irregular. A concave polygon is a polygon in which at least one of its interior angles is greater than 1

From playlist Classify Polygons

Putnam Exam | 2013: A1

We present a solution to question A1 from the 2013 William Lowell Putnam Mathematical Competition. http://www.michael-penn.net http://www.randolphcollege.edu/mathematics/

From playlist Putnam Exam Solutions: A1/B1