In Opus, a useful function is the ability to draw Circles. The instructions below illustrate how this is done.
Circles To draw a circle the user can select the command from either the New menu ( New > Circle) or by clicking on the Circle Icon 
on the Tool Bar or by typing CIRCLE or C in the program.
The user will be prompted for the Centre Point of the Circle. This point can be selected with the mouse or entered as co-ordinates.500,500
The user will then be prompted for the size of the circles radius, again this can be selected by positioning the mouse or by entering a Value.
The completed circle will be drawn and can be offset by using the Move command.