This is a 2d arc module for OpenSCAD that works for any angle between 0 and 360.. It takes arguments for the outside radius, thickness, and angle of the arc. It works by intersecting a ring with one or more triangles to create an arc. For every 90 degrees of arc, another triangle is added.
arc(radius, thick, angle);
radius: Outside radius of the arc
thick: Thickness between the outside and inside radii
angle: The angle of the arc, anywhere between 0 and 360.
linear_extrude(height) can be used to make it 3d.