# Shape Sequences: What is the next

Which is the next shape in this picture :

Source: Iranian Ph.D. University entrance exam 2017

Consider the following augmentation to the set of shapes

The rule for going from shape $N$ to $N+1$ is

Reflect all segments in the blue-red axis which are within $N$ segments of the red side. Then rotate the blue-red axis anti-clockwise.

Hence, the next shape will be

The fourth one