How can I find the normals of a Dodecahedron in rational numbers?

  • Thread starter TheDestroyer
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In summary, the normals of a dodecahedron are the lines perpendicular to its faces and there are 12 of them. They can be calculated by finding the cross product of two adjacent edges on each face. The purpose of the normals is to help with lighting and shading in computer graphics. The length of the normals can vary, but they are all perpendicular to their respective faces. They cannot be directly used to calculate the volume of a dodecahedron, which can be done using other methods.
  • #1
TheDestroyer
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Hello guys,

I need the normals of a Dodecahedron (fully symmetric 12 facets' polyhedron) given in rational numbers. I got tired searching the internet for that, so I expect something like:

{-Sqrt[1 + 2/Sqrt[5]], 0, 1/2 Sqrt[1/10 (5 - Sqrt[5])]]}

I tried Mathematica, but it gives 20 Faces for a Dodecahedron! Apparently there are repeated facets and it uses some systematic way to draw the Dodecahedron. The code I use to get the Facets in Mathematica is:

PolyhedronData["Dodecahedron", "Faces"]

Any help is highly appreciated.

Thanks.
 
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  • #2
I'm afraid there is no way other than calculate the equations of all faces.
 

FAQ: How can I find the normals of a Dodecahedron in rational numbers?

What are the normals of a dodecahedron?

The normals of a dodecahedron are the lines perpendicular to its faces. There are 12 faces on a dodecahedron, so there are 12 normals.

How are the normals of a dodecahedron calculated?

The normals of a dodecahedron can be calculated by finding the cross product of two adjacent edges on each face. This will result in a vector that is perpendicular to the face and represents the normal.

What is the purpose of the normals on a dodecahedron?

The normals of a dodecahedron are important for calculations involving lighting and shading in computer graphics. They help determine how light will interact with the surface of the dodecahedron.

Are all the normals on a dodecahedron the same length?

No, the length of the normals on a dodecahedron can vary depending on the size and shape of the dodecahedron. However, all normals on a given dodecahedron will be perpendicular to their respective faces.

Can the normals of a dodecahedron be used to calculate its volume?

No, the normals of a dodecahedron are not directly used to calculate its volume. The volume of a dodecahedron can be calculated using other methods, such as dividing it into smaller shapes and using their known volume formulas.

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