Length of an arc between two angles

Task

Calculate the length of the arc (green) between two angles;

https://imgur.com/a/aYgDLxr

It is important in video game programming

implement a method that takes parameters like:

• xpos of the circle
• ypos of the circle
• radius
• ang1
• ang2

return green arc_lenght

example method:

arc_lenght (xpos, ypos, radius, ang1, ang2) { return arc_lenght; }