Definition of angle:
Static definition of 1. Angle: A graph composed of two rays passing through a common point is called an angle. this
This point is called the vertex of the angle, and these two rays are called the two sides of the angle.
② Dynamic definition of angle: the graph formed by light rotating from one position to another around its endpoint is called angle, the endpoint of the rotated light is called the vertex of the angle, the light at the starting position is called the beginning edge of the angle, and the light at the ending position is called the ending edge of the angle.
In other words, an angle has two sides, both of which are rays, and the vertices are still together (it is a point).
Your painting has three sides. If you have to call it an angle, you can think of it as four angles, two right angles and two right angles.