Constrain keys
Constrain keys let you restrict how objects are drawn or edited. For example, when drawing a line, you can constrain it to be perfectly horizontal or vertical. You can also change which key is used as the constrain key. You can change the constrain key from Ctrl to Shift, which is the Windows standard.
To constrain an object while drawing or editing
A rectangle is constrained to a square, an ellipse to a circle, and a polygon to a shape that has sides of equal length.
To change the direction of a line that you’re drawing, release Ctrl, and move the pointer in the direction you want. Then, hold down Ctrl again to restrict movement of the pointer to the constrain angle.
To change the constrain angle, click Tools 
Options Corel DESIGNER. Click Edit, and type a value in the Constrain angle box.
To change the constrain key