Lost in space
Geometry
Level
3
A point \(P\) in \(\mathbb{R}^{3}\) has distances of \(3,7,8,9\) and \(11\) from five of the vertices of a regular octahedron. If the distance from the sixth vertex of the octahedron to \(P\) is \(\sqrt{a}\), where \(a\) is a positive, square-free integer, then find \(a \).
by
Brian Charlesworth