32 replies to this topic

[David Meadows]

Nuh huh, a icosohedron has 20 regular triangular faces. The greatdodecahedron has 12 intersecting pentagonal faces.

Yes, I know this. However:

These are the same basic shape, and they are both icosohedrons. The one of the left has 20 regular triangular faces. So does the one on the right. I can see them. You could move the image on the right over the one on the left and every line would match up, every angle would match up. They are the same shape. The indents in the one on the right are a smokescreen, and don't change the fact that the faces that make the shape are all triangles and there are 20 of them.

Hmm, ok I've just read the wiki entry and it does claim it has pentagons. This does not match the evidence of my eyes, though. Those are triangles. What trickery is going on here?

Edited by David Meadows, 11 March 2012 - 12:04 AM.

[Todd Gross]

Bottom line: Bruce is a witch!

BURN HIM!!!!


Sent from my iPhone using Tapatalk

[David Meadows]

I am currently holding one of my D20s over the shape on the left and another over the shape on the right. They fit both perfectly. Those are both icosohedrons.

I am seriously baffled

[brucegray666]

I can see where you're coming from David but I'm going to stick by my guns and say they're two distinct shape (though closely related).

To be honest, I find it pretty hard to spot the 12 distinct faces myself in the diagram. I've never seen a properly completed one in real life either. Hopefully I''ll be able to do a proper job putting one together tomorrow.

[David Meadows]

I'm not saying you're wrong, Bruce, I just don't understand it My knowledge of geometrical terminology isn't good enough to understand what the wiki page is saying.

[Mike]

I've always eyed topology suspiciously ever since I first encountered a Möbius strip.

[brucegray666]

Math's teacher confession: neither is mine! I'm useless at all this real life, concrete example stuff.

This website - http://mathworld.wol...decahedron.html - has a nice wee interactive Java model which seems to have the 12 distinct, intersecting faces shaded in a different colour. Maybe that'll help you see the 12 rather than the 20.

[Henry Blanco]

Bottom line: Bruce is a witch!

BURN HIM!!!!

Did you dress him up like that?

[Todd Gross]

Did you dress him up like that?

But he has got a wart!


Sent from my iPhone using Tapatalk

[njerry]

If he floats, he's a witch!

Hey Folks!

Just dropped by library - all is "fine". Should have my computer back in a week or so.

Miss ya!

-M.

Miss you too, Miqque.

[steveuk]

Good morning all.

 coffee_001.jpg   65.61K   0 downloads

[brucegray666]

If he floats, he's a witch!

Actually, I'm a duck.

[David Meadows]

Help, brain exploding!