In geometry, the small ditrigonal icosidodecahedron (or small ditrigonary icosidodecahedron) is a nonconvex uniform polyhedron, indexed as U30. It has 32 faces (20 triangles and 12 pentagrams), 60 edges, and 20 vertices. It has extended Schläfli symbol a{5,3}, as an altered dodecahedron, and Coxeter diagram or . It is constructed from Schwarz triangle (3 3 5⁄2) with Wythoff symbol 3 | 5⁄2 3. Its hexagonal vertex figure alternates equilateral triangle and pentagram faces. (Wikipedia).
Platonic and Archimedean solids
Platonic solids: http://shpws.me/qPNS Archimedean solids: http://shpws.me/qPNV
From playlist 3D printing
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
A few of the settings I like to customise in Stella4D - a powerful polyhedra program. Stella4D website: http://www.software3d.com/Stella.php My website with lots of polyhedra resources: www.maths-pro.com
From playlist MASA
2020 Auction Fundraiser - Zoom Preview
2020 Auction Webpage: http://www.gathering4gardner.org/auction2020/ ** Auction Preview Timestamps: ** 00:20 – Bob Hearn – introduction and auction explanation 05:00 – G4G branded face mask give-away 05:45 – John Conway’s traveling backgammon game 06:00 – Autographed books 07:15 – Adam Rubi
From playlist Celebration of Mind
LMS Popular Lecture Series 2008, Know your Enemy, Dr Reidun Twarock
LMS Popular Lecture Series 2008, Know your enemy - viruses under the mathematical microscope, Dr Reidun Twarock
From playlist LMS Popular Lectures 2007 - present
S.A.Robertson, How to see objects in four dimensions, LMS 1993
Based on the 1993 London Mathematical Society Popular Lectures, this special 'television lecture' is entitled "How to see objects in four dimensions" by Professor S.A.Robertson. The London Mathematical Society is one of the oldest mathematical societies, founded in 1865. Despite it's name
From playlist Mathematics
Canonical structures inside the Platonic solids III | Universal Hyperbolic Geometry 51
The dodecahedron is surely one of the truly great mathematical objects---revered by the ancient Greeks, Kepler, and many mathematicians since. Its symmetries are particularly rich, and in this video we look at how to see the five-fold and six-fold symmetries of this object via internal str
From playlist Universal Hyperbolic Geometry
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
What are the names of different types of polygons based on the number of sides
👉 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
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
What is the difference between convex and concave 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
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
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
What is the difference between a regular and irregular polygon
👉 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
Scotland Ruby 2011 - What Ruby Can Learn From Smalltalk
by: Steven Baker Smalltalk is one of the forefathers of Object Oriented programming, and has a long history of being used in the field. One of the quiet players, many have heard of Smalltalk without having worked with it, but Smalltalk is indispensable in many industries including insuran
From playlist Scotland Ruby 2011
MountainWest RubyConf 2014 - But Really, You Should Learn Smalltalk
By Noel Rappin Smalltalk has mystique. We talk about it more than we use it. It seems like it should be so similar to Ruby. It has similar Object-Oriented structures, it even has blocks. But everything is so slightly different, from the programming environment, to the 1-based arrays, to t
From playlist MWRC 2014
Lec 11 | MIT 6.002 Circuits and Electronics, Spring 2007
Small signal circuits View the complete course: http://ocw.mit.edu/6-002S07 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT 6.002 Circuits and Electronics, Spring 2007
PrepTest 5 Game 2: A Grouping Game with No Groups // Logic Games [#18] [LSAT Analytical Reasoning]
We've seen a grouping game with no elements before (https://youtu.be/5U0mlFdeZ6c), so how about a grouping game with no groups. This is the second game of the June 1992 LSAT games section. I suppose it's not quite right to say it has no groups. The way I diagram it is as if there are three
From playlist LSAT Games
What is the difference between concave and convex 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