# Math Help - Trying to find the length of a curve.

1. ## Trying to find the length of a curve.

Hello everyone. I'm trying to find the length of a curve from the center line to the distance. I need to fit a bolt bar at 21" from the center line. I need to find the length of the curve in inches or degrees or both if possible. Theres a link below to a picture of what Im trying to do. Please help and thank you for your time.

This is the formula I have: Distance divided by radius multiplied by sin multiplied by one degree.

http://i815.photobucket.com/albums/z...ezerg/Sin1.jpg

2. arclength ...

$s = r \cdot \theta$

$s = 60 \cdot \arcsin\left(\frac{21}{60}\right) \approx 21.454$ inches

3. ok but 21" is not the length of the arc, its the distance from the center line to where I want to fit the bolt bars.

4. Originally Posted by Davezerg
ok but 21" is not the length of the arc, its the distance from the center line to where I want to fit the bolt bars.
I know that. the length of the arc is 21.454 in