The next diagram reveals how to utilize Perfectagøn to create a tetragon.
Utilizing Perfectagøn for the tetragon reveals that you could intersect Line B with segment two resulting in a tetragon at a different orientation. Since the intersection with segment two passes through the center of Circle A and segment four intersects with a point on Circle A exactly one fourth the circumference, both will render a perfect tetragon. All of the examples illustrating Perfectagøn produce regular polygons with a point at the top. Of course the Perfectagøn Base Setup could be established at any angle.