Problem

Source: 45th International Tournament of Towns, Junior O-Level P2, Fall 2023

Tags: geometry



2. The quadrilateral $A B C D$ is convex. Its sides $A B$ and $C D$ are parallel. It is known that the angles $D A C$ and $A B D$ are equal. Furthermore the angles $C A B$ and $D B C$ are equal. Is $A B C D$ necessarily a square? Alexandr Terteryan