You can restrict how objects are drawn
and edited by using a constrain key while you draw. For example, you can press a
constrain key to constrain a rectangle to a square, an ellipse to a circle, or a
straight line to a perfectly horizontal or vertical line. By default, the
application uses the Ctrl key to constrain the shape or angle of objects, and
the Shift key to draw shapes outward from their center of origin. However, you
can change the default constrain key to Shift at any time.
Using a constrain key lets you draw or rotate an object or an object’s nodes and
control handles at a preset increment, known as a constrain angle. By default,
the constrain angle is 15 degrees, but you can change it to suit your needs.
Process to constrain objects while
drawing or editing