The circle drawing function will be used to denote features such as Centre Pivot irrigators. To draw a circle:
•Select the layer you want to draw the circle on (will need to be a Polygon Layer).
•Click on the Drawing button 
•From the Drawing Toolbar, select the Draw Circle button 
•With the cursor, left mouse click and hold down over the centre of where the circle is to be positioned. With the left mouse button still held down, drag the cursor out until the pointer reaches the outer most part of the circle and then release the left mouse button.
•Click the Stop Drawing button 
