8.2 Drawing a rectangle with chosen dimension

We define here a procedure called rec depending on two variables representing the dimensions of the rectangle. Hence rec 200 100 will draw a rectangle with height 200 and width 100.

to rec :lo :la  
repeat 2 [forward :lo right 90 forward :la right 90]  

Make some examples:

rec 200 100 rec 100 300 rec 50 150 rec 1 20 rec 100 2

If we give to the procedure rec only one number, the interpreter will send an error message indicating that the procedure is waiting for a second argument.