Editing Talk:2781: The Six Platonic Solids

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:But... Take a regular polygon (...as in a "flat shape that has equal angles/side-lengths and no internal angles"...) join it up with other (identical) polygons to create a regular ''3D'' shape. The Platonic solids are the full set of these that aren't: a) flat, an infinite plane, b) angled both inwards and outwards, c) self-crossing its surfaces, d) leaves gaps, e) have different-looking corners, ....etc.
 
:But... Take a regular polygon (...as in a "flat shape that has equal angles/side-lengths and no internal angles"...) join it up with other (identical) polygons to create a regular ''3D'' shape. The Platonic solids are the full set of these that aren't: a) flat, an infinite plane, b) angled both inwards and outwards, c) self-crossing its surfaces, d) leaves gaps, e) have different-looking corners, ....etc.
 
:It can be shown that (given the above restrictions): a square can be used only to make a cube; a triangle can make a tetrahedron (triangular-based pyramid), an octahedron (two square-based pyramids stuck base-to-base) or an icosahedron (a twenty-sided solid); a pentagon can make a dodecahedron (a twelve-sided solid); no other combinations are possible. Hexagons will tile infinitly (or create a flat 'double-sided' free-floating hexagonal plate) heptagons and more won't even tile. There are thus five of these 'basic' regular solids, described by/ascribed to Plato, as seen (discounting the jorb).
 
:It can be shown that (given the above restrictions): a square can be used only to make a cube; a triangle can make a tetrahedron (triangular-based pyramid), an octahedron (two square-based pyramids stuck base-to-base) or an icosahedron (a twenty-sided solid); a pentagon can make a dodecahedron (a twelve-sided solid); no other combinations are possible. Hexagons will tile infinitly (or create a flat 'double-sided' free-floating hexagonal plate) heptagons and more won't even tile. There are thus five of these 'basic' regular solids, described by/ascribed to Plato, as seen (discounting the jorb).
:Further 'regular' shapes exist if you undo some of the restrictions (infinite sheets, alternating in-and-out angles, using regular self-crossing shapes and/or allowing the shapes to cross each other whilst forming the solid, etc... e.g. for which someone else recently added links to the additional set of 'stellated' regular polyhedra). Or abandon Euclidean space/expand beyond three dimensions (both of which make Platonic solids no longer fully valid, at the same time). And if you consider "regular convex polyhedra" beyond you, at this point where you've already seen links to a potential wikiwalk to fill in gaps in your knowledge about what these terms mean, then I'm not sure what more I can say. Either here or in the main Explanation. Not without hand-holding you through points that I learnt in maths lessons when I was no more than 11 (and probably already knew, at least in parts). Can't account for current practice, or the localised curriculum that you were taught, of course, but then a 'refresher' or post-education remedial 'filler' lesson isn't going to be possible just through a paragraph or two of blind monologue. Check the links, and ask more specific questions than just not understanding any of it. [[Special:Contributions/172.71.178.66|172.71.178.66]] 10:24, 23 January 2024 (UTC)
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:Further 'regular' shapes exist if you undo some of the restrictions (infinite sheets, alternating in-and-out angles, using regular self-crossing shapes and/or allowing the shapes to cross each other whilst forming the solid, etc... e.g. for which someone else recently added links to the additional set of 'stellated' regular polyhedra). Or abandon Euclidean space/expand beyond three dimensions (both of which make Platonic solids no longer fully valid, at the same time. And if you consider "convex polyhedra" beyond you, at this point where you've already seen links to a potential wikiwalk to fill in gaps in your knowledge about what these terms mean, then I'm not sure what more I can say. Either here or in the main Explanation. Not without hand-holding you through points that I learnt in maths lessons when I was no more than 11 (and probably already knew, at least in parts). Can't account for current practice, or the localised curriculum that you were taught, of course, but then a 'refresher' or post-education 'filler' lesson isn't going to be possible just through a paragraph or two of blind monologue.

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