Function right_angle

right_angle(p: [Vector2, Vector2, Vector2], size?: number): Diagram
Create an annotation for right angle make sure the angle is 90 degree
Parameters
- p: [Vector2, Vector2, Vector2]
  three points to define the angle
- size: number = 1
  size of the square
Returns Diagram
- Defined in shapes/shapes_annotation.ts:95