MathDB

Chisinau MO p105 1975 R2 VIII A, B, M, K conyclic if AB=BC=CD

Source:

March 16, 2021

geometryConcyclicequal segments

Problem Statement

Let

M

be the point of intersection of the diagonals, and

K

be the point of intersection of the bisectors of the angles

B

and

C

of the convex quadrilateral

ABCD

. Prove that points

A, B, M, K

lie on the same circle if the following relation holds:

|AB|=|BC|=|CD|