Figurate numbers

Centered dodecahedral number

A centered dodecahedral number is a centered figurate number that represents a dodecahedron. The centered dodecahedral number for a specific n is given by The first such numbers are 1, 33, 155, 427, 909, 1661, 2743, 4215, 6137, 8569, … (sequence in the OEIS). (Wikipedia).

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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

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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

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The Pop-up Dodecahedron

Instruction to download http://singingbanana.com/popupdodecahedron.pdf More information about the dodecahedron that I would have like to have gone into in this video http://uk.youtube.com/watch?v=-lqpSpje42o Dodecahedron at wikipedia http://en.wikipedia.org/wiki/Dodecahedron Plato

From playlist My Maths Videos

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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

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How to find the volume of a pentagonal pyramid

👉 Learn how to find the volume and the surface area of a pyramid. A pyramid is a 3-dimensional object having a polygon as its base and triangular surfaces converging at a single point called its apex. A pyramid derives its name from the shape of its base, i.e. a pyramid with a triangular b

From playlist Volume and Surface Area

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How do ceramic crystal structures differ from metal crystal structures?

Metal crystal structures are much simpler than ceramic structures. This is due to two reasons. First, ceramics have positive and negative charged ions. Cations and ions must maintain charge neutrality. Second, the size of cations and anions are very different! Structures with multiple diff

From playlist Materials Sciences 101 - Introduction to Materials Science & Engineering 2020

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What are the trigonometric definitions of a right triangle

👉 Learn all about the trigonometry of right triangles. A right triangle is a triangle that has 90 degrees as one of its angles. The trigonometric identities of right triangles give us the relationship between the angles of a right triangle and the side lengths of the right triangle. These

From playlist Right Triangle Trigonometry | Learn About

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To Build Viruses: A Markov Chain Monte Carlo Algorithm for Stimulating Viral Assembly Kinetics

For the latest information, please visit: http://www.wolfram.com Speaker: Nicholas Brunk Wolfram developers and colleagues discussed the latest in innovative technologies for cloud computing, interactive deployment, mobile devices, and more.

From playlist Wolfram Technology Conference 2015

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"Illustrating Geometry" exhibition at SCGP, Artist's talk: "Sculpture in four-dimensions"

Slides: http://www.math.okstate.edu/~segerman/talks/sculpture_in_4-dimensions.pdf This video is also available at the Simons Center website, at http://scgp.stonybrook.edu/archives/11540 Thanks to Josh Klein for filming and editing.

From playlist 3D printing

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Rhombofoam in Zome – Scott Vorthmann

Rhombofoam is a pattern that fills 3D space in all the ways that a golden rhombohedron does, while forming dodecahedral and 16-sided cells that have the topology of foam: three cells around each edge, and four around each vertex. The result is a foam model that has the symmetries of a quas

From playlist G4G12 Videos

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Day 14 ceramic crystal structures

0:00 reading quiz 5:25 HCP structure and close-packing 10:27 theoretical density calculation 15:00 difference between observed and theoretical densities 18:16 ceramic crystal structures and using rc/ra ratio to determine coordination 23:26 rock salt (NaCl) structure 29:28 cesium chloride (

From playlist Introduction to Materials Science and Engineering Fall 2017

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ceramic crystal structures

0:00 coordination of hexagonal close-packed HCP structure 4:40 theoretical density 21:37 structure of ceramics using cation/anion ratio 30:65 NaCl rock salt structure 33:05 CsCl structure 35:18 ZnS zinc blende structure 39:00 solving for lattice parameter in terms of cation and anion radii

From playlist Introduction to Materials Science & Engineering Fall 2019

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Henry Segerman - 3D Shadows: Casting Light on the Fourth Dimension - 02/11/17

Henry Segerman "3D Shadows: Casting Light on the Fourth Dimension" February 11, 2017 Wesier Hall Ann Arbor, Michigan

From playlist 3D printing

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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

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What is the tangent function

👉 Learn all about the trigonometry of right triangles. A right triangle is a triangle that has 90 degrees as one of its angles. The trigonometric identities of right triangles give us the relationship between the angles of a right triangle and the side lengths of the right triangle. These

From playlist Right Triangle Trigonometry | Learn About

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Using a set of points determine if the figure is a parallelogram using the midpoint formula

👉 Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr

From playlist Quadrilaterals on a Coordinate Plane

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The unexpected logic behind rolling multiple dice and picking the highest.

Check out Jane Street's icosahedron puzzle: https://www.janestreet.com/IMO2022/ 2022 International Mathematical Olympiad! https://www.imo2022.org/ If you want those d60 and d120 we sell them on Maths Gear or you can go direct to The Dice Lab. https://mathsgear.co.uk/collections/dice http

From playlist Prob and Stats

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Bridges 2014 talk: The quaternion group as a symmetry group

This is a talk I gave at the Bridges conference on mathematics and the arts (http://bridgesmathart.org/), on 18th August 2014, about my paper with Vi Hart with the same title. The slides are available at https://www.math.okstate.edu/~segerman/talks/quaternion_group_as_a_symmetry_group.pdf

From playlist 3D printing

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Area of dodecagon from a square!

This is a short, animated visual proof demonstrating that the area of a regular dodecagon inscribed in the unit circle has an area of exactly 3. #math​ #manim​ #visualproof​ #mathvideo​ #geometry #mathshorts​ #geometry #mtbos​ #animation​ #theorem​ #pww​ #proofwithoutwords​ #proof​ #it

From playlist MathShorts

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Infinity | Dodecahedron | Figurate number