MathDB
Moving P(o)in(t)s

Source: USAJMO 2021/4

April 15, 2021
USA(J)MOUSAJMO2021 usajmo

Problem Statement

Carina has three pins, labeled A,BA, B, and CC, respectively, located at the origin of the coordinate plane. In a move, Carina may move a pin to an adjacent lattice point at distance 11 away. What is the least number of moves that Carina can make in order for triangle ABCABC to have area 2021?
(A lattice point is a point (x,y)(x, y) in the coordinate plane where xx and yy are both integers, not necessarily positive.)