Regular Networks on Torus: Can't Have Pentagons as Faces?

In summary, the conversation discusses the idea of regular networks on a torus, given the formula V - E + F = 0. The speaker is asked to prove that it is impossible to have a regular network on a torus with pentagons as faces. The conversation also delves into the concept of tessellation and how it relates to pentagons.
  • #1
Zurtex
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I'm asked to consider regular networks on a torus. I'm given that V - E + F = 0. I need to show it is impossible to have a regular network on a torus where the faces are pentagons; I don't understand that at all. Surely it is easy to have pentagons as faces… All you would need to is draw a pentagon on it, please tell me where I am not getting this.
 
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  • #2
I suspect that what they mean is a network that completely covers the torus: every point on the torus in on or inside some pentagon.

Suppose your network consisted of n pentagons. Then there are n faces. How many edges are there? (Each pentagon has 5 edges, but each edge is shared by two pentagons.) How many vertices are there? (Each pentagon has 5 vertices but each vertex is shared by 3 pentagons.)

Now plug those numbers into the Euler equation.
 
  • #3
Thanks :smile:
 
  • #4
Erm writing this out, I'm confused again. How can all shapes be a pentagon in a regular network anyway? Pentagons don't tessellate.
 

Related to Regular Networks on Torus: Can't Have Pentagons as Faces?

What is a regular network on a torus?

A regular network on a torus is a mathematical construct that represents a network of points or vertices connected by edges on a torus-shaped surface. This can be visualized as a grid-like structure on the surface of a donut.

Why can't regular networks on a torus have pentagons as faces?

This is due to a mathematical principle known as the Euler characteristic, which states that the number of vertices (V), edges (E), and faces (F) of a regular network on a torus must follow the equation V-E+F=0. Since a pentagon has an odd number of edges (5), it would disrupt this balance and violate the Euler characteristic.

What are the consequences of having pentagons as faces in a regular network on a torus?

If pentagons were allowed as faces in a regular network on a torus, it would result in a network that is not symmetric and would not be considered a true regular network. This could cause inaccuracies and complications in any mathematical calculations or analyses done using the network.

Can a regular network on a torus have other types of faces besides squares?

Yes, a regular network on a torus can have faces of other shapes, such as hexagons or octagons. As long as the faces have an even number of edges, it will not violate the Euler characteristic and will still be considered a regular network on a torus.

Are there any real-life applications of regular networks on a torus?

Regular networks on a torus have been studied in mathematics and topology, and have been used to model various systems in physics, such as the structure of crystals. They have also been used in computer graphics and animation to create seamless patterns and textures.

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