Assume we have an arbitrary polygon that has no holes nor self edge intersections, but can otherwise be concave and deformed.
Assume the vertices are ordered either clockwise or ccw.
So for example the following:
The angle at the blue vertex is greater than 180 in this case. Beause that is the angle "inside" the polygon.
Usually when I want to measure angles in a shape I just take the dot product, but that will always give back an angle <180, which is not ideal.
Assuming that all I have is an ordered list of the vertices of the polygon. How can I measure the appropriate angle?