 
 
 
The parallelogram command takes three mandatory arguments and one optional argument. The mandatory arguments are three points A, B and C.
parallelogram returns and draws the parallelogram
ABCD for the appropriate D.
Input:
Output:
 
The fourth optional argument will need to be
a variable name which will be assigned to vertex D.
Input:
Output:
 
Input:
Output:
 
 
