To draw a rectangle you will need to points which are the end points of its diagonal. To draw a select rectangle option from Insert toolbar or select icon from Entity toolbar. Then mark first point and then second, you will get a drawing of rectangle. For this see figure given below
From above figure you can understand the that how to draw a rectangle.
Steps to draw :
Select 'Rectangle' tool from Insert menu or from Entity toolbar.
Mark 1st point (P1) s shown in fig.
Then go for the 2nd point (P2) ,opposite corner point.