Before tackling this one, take a look at this one.

     +-------------D
    /|            /|
   / |           / |
  /  |          /  |
 /   |         /   |
C-------------+    |
|    |        |    |
|    B--------|----+
|   /         |   /
|  /          |  /
| /           | /
|/            |/
+-------------A

A, B, C and D are non-adjacent vertices of a cube. There is a point P in space such that PA=3, PB=5, PC=7, and PD=6. Find the distance from P to the other four vertices and find the length of the edge of the cube.
There are two answers, one with P outside the cube and one with P inside the cube.

(In reply to My numbers were wrong. by John)

The distances to the four other points agree numerically with those found only numerically by successive approximations, assuming that the undisplayable character is a square root sign.  The one for the length of the edge is so scrambled by the input rich text box that I can't tell what it is.

Posted by Charlie on 2004-07-27 15:48:48