MathDB

1

Part of 1987 Austrian-Polish Competition

Problems(1)

sum of squares of 3 pairwise orthogonal chords of sphere independent APMC 87

Source:

5/19/2019
Three pairwise orthogonal chords of a sphere SS are drawn through a given point PP inside SS. Prove that the sum of the squares of their lengths does not depend on their directions.
geometry3D geometrysphereChords