[Math] Radius of circle by knowing a cross section.

circlestrigonometry

I have a curve on an ellipse where I know the length of a cross section and need to find out it's radius (vertically and horizontally) and calculate the angle of the curve.

In the following diagram I know $x$ (identical on both sides) and $y$ and need to find $r_1$, $r_2$ and $\alpha$. This seems like a fairly simple problem but i'm stumped..

edit: i also know the length of the arc

enter image description here

Best Answer

I got this answer from a friend and were able to solve it. Turns out it was a bit easier than i anticipated.

Apologies for an image as an answer (that's what i got), hopefully this still helps somebody else having the same issue:

enter image description here