Timeline for Characterizing Convex Configurations of Quadrupels of Coplanar Points via Linear (In-)equalities between Distance Sums or Differences
Current License: CC BY-SA 3.0
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| when toggle format | what | by | license | comment | |
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| Feb 24, 2013 at 12:45 | comment | added | Manfred Weis | A reconstruction of a set of 4 points $A$,$B$,$C$ and $D$, whose distance equal the given $AB$,$BC$,$CD$,$DA$,$AC$ and $BD$ is fairly easy: construct triangle $ABC$ from the given lengths, then construct the intersection point of a circle around $A$ with radius $AD$ and around $B$ with radius $BD$ and chose as $D$ the intersection point, whose distance from $C$ equals $CD$; but how does it help to determine without visual inspection, whether the convex hull of $A$,$B$,$C$ and $D$ has four corners and, apart from that, circles are quadratic algebraic curves. | |
| Feb 24, 2013 at 1:03 | history | answered | Aaron Meyerowitz | CC BY-SA 3.0 |