MathDB
3 rays in space

Source: Poland MO 1995

August 24, 2005
geometry unsolvedgeometry

Problem Statement

PA,PB,PCPA, PB, PC are three rays in space. Show that there is just one pair of points B,CB', C' with BB' on the ray PBPB and CC' on the ray PCPC such that PC+BC=PA+ABPC' + B'C' = PA + AB' and PB+BC=PA+ACPB' + B'C' = PA + AC'.