Rhombuses in the plane: rhombus

### 13.9.2 Rhombuses in the plane: rhombus

See Section 14.8.2 for rhombuses in space.

The rhombus command creates rhombuses.

- rhombus takes three mandatory arguments and two optional arguments.
  - A,B, two points.
  - a, a real number.
  - Optionally, varc, vard, two variable names.
- rhombus(A,B,a ⟨varc,vard⟩) returns and draws the rhombus ABCD, where a is the counterclockwise angle from AB to AC. If the arguments varc and vard are given, then C and D will be assigned to them.

Examples.

- Input:
  rhombus(-2*i, sqrt(3) - i, pi/3)
  Output:
- Input:
  rhombus(-2*i, sqrt(3) - i, pi/3, C, D)
  Output:
  Input:
  affix(C), affix(D)
  Output:

  | √ |
  3
  | + i, 0