### 12.10.2 Regular polygons in the plane: isopolygon

See section 13.9.2 for regular polygons in space.

The isopolygon command takes three arguments; two points A and B and a non-zero integer k.

isopolygon returns and draws the regular |k|-sided polygon with one side AB. If k > 0, then the polygon will continue counterclockwise; if k < 0, then it will be clockwise.
Input:

isopolygon(0,1,4)

Output:

Input:

isopolygon(0,1,-4)

Output: