How to dynamically create a ring mesh that builds from a center point?

Hello! I am new here, so please feel free to scold me if there's anything wrong with this question. I've searched all over and can't quite find the solution, so here goes.



As above, I'm looking to dynamically create a slice of a 2D ring, like an arc, with a mesh for collisions. Through other online searches, I came across a nearly perfect example file on reddit here. My issue is that the arc builds in one direction from a single point. Ideally, I'd like to have the arc build in both directions (CW and CCW) because I'm going to be adjusting the angle of the slice dynamically in gameplay. Currently, making any adjustments to the angle results in an off-center slice which becomes cumbersome to manipulate by the user.

If preferable I can include the code in this post, but I opted for a link above in order to keep this as brief as possible.

Thank you in advance to all who read!