Search: subworld:curves_and_fill_shapes_drawing
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BP935 |
| Shapes have equal area vs. not so. |
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BP937 |
| Shapes have equal perimeter vs. not so. |
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BP990 |
| The center of mass can "see" (in straight lines) all points within the shape vs. the center of mass is not located in a region where it can see (in straight lines) all points. |
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BP991 |
| Can be arranged with multiple copies of itself to form some convex shape vs. not so. |
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BP992 |
| Concave shapes with concave cavities vs. convex cavities |
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COMMENTS
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All examples in this Problem are solid concave black shapes. In this Problem, the "cavities" of a concave shape are defined to be the convex hull of the shape minus the shape itself. For example, if you take a bite out of the edge of a piece of paper, the piece of paper in your mouth is the cavity of the bitten piece of paper. The idea may be indefinitely extended, considering whether the cavities of the cavities are concave or convex, and so on. |
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CROSSREFS
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Adjacent-numbered pages:
BP987 BP988 BP989 BP990 BP991  *  BP993 BP994 BP995 BP996 BP997
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KEYWORD
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nice, precise, perfect, traditional
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CONCEPT
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recursion_number (info | search), recursion (info | search)
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WORLD
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concave_fill_shape [smaller | same | bigger]
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AUTHOR
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Jago Collins
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BP1011 |
| Polygon can be inscribed in a circle vs. not so. |
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REFERENCE
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Henneberg, L. (1911), Die graphische Statik der starren Systeme, Leipzig
Jackson, Bill. (2007). Notes on the Rigidity of Graphs.
Laman, Gerard. (1970), "On graphs and the rigidity of plane skeletal structures", J. Engineering Mathematics, 4 (4): 331–340.
Pollaczek‐Geiringer, Hilda (1927), "Über die Gliederung ebener Fachwerke", Zeitschrift für Angewandte Mathematik und Mechanik, 7 (1): 58–72. |
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CROSSREFS
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Adjacent-numbered pages:
BP1011 BP1012 BP1013 BP1014 BP1015  *  BP1017 BP1018 BP1019 BP1020 BP1021
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KEYWORD
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nice, physics, help
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CONCEPT
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rigidity (info | search), graph (info | search), imagined_motion (info | search)
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WORLD
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planar_connected_graph [smaller | same | bigger] zoom in left (rigid_planar_connected_graph)
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AUTHOR
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Aaron David Fairbanks
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BP1055 |
| Equidiagonal quadrilaterals vs. non-equidiagonal quadrilaterals |
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