Indian Mathematical Olympiad 1988 - Problem 8
Source:
August 14, 2009
vectorgeometry proposedgeometry
Problem Statement
A river flows between two houses and , the houses standing some distances away from the banks. Where should a bridge be built on the river so that a person going from to , using the bridge to cross the river may do so by the shortest path? Assume that the banks of the river are straight and parallel, and the bridge must be perpendicular to the banks.