MathDB
d(A,ll)> d(P, AQ), distances inequality with 3 collinear points Chile 2010 L2 P5

Source:

May 31, 2019
geometrygeometric inequalitydistance

Problem Statement

Consider a line \ell in the plane and let B1,B2,B3 B_1, B_2, B_3 be different points in \ell. Let A A be a point that is not in \ell. Show that there is P,Q P, Q in B1,B2,B3 {B_1, B_2, B_3} with PQ P \ne Q so that the distance from A A to \ell is greater than the distance from P P to the line that passes through A A and Q Q .