#### Example.

Input:

circle(point(0,0,1),point(0,1,0),point(0,2,2))

Output:

Two points and a vector.

- circle takes three points:
  - C, a point (which can be given by its coordinates).
  - v, a vector.
  - A, a point (which can be given by its coordinates).
- circle(C,v,A) returns and draws the circle in plane C(C+v)C with center C and containing C+v.

#### Example.

Input:

circle(point(0,0,1),vector(0,1,0),point(0,2,2))

Output: