For an irregular polygon in a circle, the "Sum of all central angles is 2π".
The sum of the outer internal angles is 180 * (number of sides - 2). 180*(5-2) = 540 degrees.
So with the unknown being the rotation angle of the right unit chord,
the angle (~114.82 degrees) between two unit chords can be calculated, with a little simple math.

So devise a method to draw the right chord leg, and the right chord arm, with the changing rotation, (~97.75degrees), and snap the endpoint to top center, as the pair of chords is rotated.

https://math.stackexchange.com/questions/3184676/finding-the-interior-angles-of-an-irregular-polygon-inscribed-on-a-circle

- Brian

(114.82 * 3) + (97.76 * 2) = 539.98 = 540 degrees.
https://math.stackexchange.com/questions/3047152/if-the-total-number-of-angles-in-a-polygon-is-180n-2-why-are-there-just-36

Use radians instead of degrees...