A shape, formed by two lines or rays diverging from a common point (the vertex).
Anything related to concave geometric shapes
"Edit2 okay i just see that if the angle is bigger than 180â it s concave so i have to change the shape for be simple than a triangulation"
from question "Miss two vertices on PolygonShape object"
"If the total of the angle is less than 180â the triangle must be â œhyperbolicâ on a concave surface which might be the shape of our universe"
from question "If Elif Else Chain To Classify Triangle (Python)"