# Rotating Lines around an Axis or a Circle

Rotating Lines around an Axis or a Circle

Parallel line segments intersect an axis at right angles. They rotate at a rate proportional to the signed distance from the center point of the axis, creating a helicoid.

Collinear line segments intersect a circle at right angles. They rotate at a rate proportional to the distance from one point on the circle, creating a Möbius strip at the halfway mark and a doubly folded strip at time 1.