# Tagged Questions

599 views

### Icosahedron coordinates

Wikipedia says (link)that cartesian coordinates of icosahedron are: (0, ±1, ± φ) (±1, ± φ, 0) (± φ, 0, ±1) Where φ = (1 + √5) / 2 is golden ratio ≈ 1.618. I ...
372 views

### How to calculate vertices of dodecahedron using W|A?

Can I calculate for example with wolfram alpha coordinates of vertices of dodecahedron? I know coordinates of center point of dodecahedron (center of gravity) and the height of dodecahedron. Thanks ...
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### Is the Euler characteristic $\chi =2$ for the prism with a hole?

I keep getting $\chi=2$ for the solid in the picture. It's a prism with a hole joining two opposite sides. I remember reading that $\chi=0$ for such solids. Help me find my error. I'd appreciate if ...
470 views

### Radius of a Sphere inscribed in a Convex Polyhedron

My teacher gave me this problem in class as a challenge. It has stumped me for days, yet he refuses to give me the answer! Let $PQRSTU$ and $PQR'S'T 'U'$ be two regular planar ...
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### What shape is this?

im doing a question that involves a shape with 8 faces, 10 vertices and 16 edges. Can anyone enlighten me as to what this shape is called? Many Thanks