# arc

Create an arc. You can pass a 2 element vector to define the central angle. It provides a `fn` parameter consistent with the `$fn` parameter of the circle module. It depends on the `circular_sector` module so you have to include circular_sector.scad.

## Parameters

- `radius` : The radius of the circle.
- `angles` : A 2 element vector which defines the central angle. The first element of the vector is the beginning angle in degrees, and the second element is the ending angle.
- `width_mode` : The default value is `"LINE_CROSS"`. The arc line will move outward by `width /2` and inward by `width / 2`. If it's `"LINE_OUTWARD"`, the arc line moves outward by `width`. The `"LINE_INWARD"` moves the arc line inward by `width`.
- `fn` : The `$fn` value used by the `circle` module internally. The default value is 24.

## Examples

    arc(radius = 20, angles = [45, 290], width = 2);
    %circle(r = 20, $fn = 24); 

![arc](images/lib-arc-1.JPG)

    arc(radius = 20, angles = [45, 290], width = 2, width_mode = "LINE_INWARD");
    %circle(r = 20, $fn = 24); 

![arc](images/lib-arc-2.JPG)

    arc(radius = 20, angles = [45, 290], width = 2, width_mode = "LINE_OUTWARD");
    %circle(r = 20, $fn = 24); 

![arc](images/lib-arc-3.JPG)