How can you find the length of the arc formed by two points on a circle? Is there any function that draws a perfect semi-circle so you can use integrals to find the value of the arc or is there a simpler solution?
- Anybody can ask a question
- Anybody can answer
- The best answers are voted up and rise to the top
Do you know the angle formed by those two points and the center of the circle? If so, and that angle is $\theta$ in radians, and the radius of the circle is $r$, then the arc length is $$ s = r \theta.$$
Read more here.
If you don't know $\theta$, you can find it by taking the dot product of the vectors from the center to each point. More on the dot product here.