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