#### 2.7.1 Point sweeps

Sweeping a point makes a one-dimensional path, which is a polyline.
Since we have swept with a rotation, the result is a circular arc.
Here is what it looks like.

This is the first example we have seen of `sketch`

arithmetic.
The expression `180 / n_segs` causes the eight rotations to add
to 180. If you're paying attention, you'll have already noted that
there are *nine* points, producing eight line segments.

You can cause the swept point to generate a single polygon rather than
a polyline by using the closure tag `<>`
after the number
of swept objects. Code and result follow

def n_segs 8
sweep { n_segs<>, rotate(180 / n_segs, (0,0,0), [0,0,1]) } (1,0,0)