Parallelograms in the plane: parallelogram

### 13.9.4 Parallelograms in the plane: parallelogram

See Section 14.8.4 for parallelograms in space.

The parallelogram command creates parallelogram.

- parallelogram takes three mandatory arguments and one optional argument:
  - A,B,C, three points.
  - Optionally, var, a variable name.
- parallelogram(A,B,C ⟨var⟩) returns and draws the parallelogram ABCD for the appropriate D.
  If the argument var is given, then D will be assigned to it.

#### Examples

- Input:
  parallelogram(0, 1, 2 + i)
  Output:
- Input:
  parallelogram(0, 1, 2 + i, D)
  Output:
  Input:
  affix(D)
  Output:

  1+i