DeductionLocusMedium
The Locus Hunt
Find the buried chest from a single distance clue — geometry pins it exactly.
Worked demonstration
A map shows a well at (3, 3) and five trees — Banyan at (4, 3); Peepal at (10, 3); Neem at (0, 3); Mango at (8, 3); Tamarind at (6, 0). The chest is buried exactly 5 steps from the well, counting moves up, down, left or right. Which tree marks the spot?
Try it yourself
Why it works
A locus is the set of points obeying a distance rule; only one marked spot lies the stated number of steps from the well.
Background & Explore Further
Fixed-distance loci are exactly how GPS trilateration and cell-tower triangulation pinpoint your location. Explore how intersecting distance circles fix a single point.
Maths Made Magic — Queen Mary University of London (cs4fn)
