Use snap alignment

To turn on Snap Alignment, use the Snap Align command in the View menu. To select settings for Snap Alignment, use the Edit Snap Align command in the View menu.

When you select Snap Alignment settings, set the snap tolerance between horizontal or vertical edges of objects, and between objects’ edges and the Stage border. You can also turn on snap alignment between the horizontal and the vertical centers of objects. All Snap Alignment settings are measured in pixels.

When Snap Alignment is turned on, dotted lines appear on the Stage when you drag an object to the specified snap tolerance. For example, if you set Horizontal snap tolerance to 18 pixels (the default setting), a dotted line appears along the edge of the object you are dragging when the object is exactly 18 pixels from another object. If you turn on Horizontal Center Alignment, a dotted line appears along the horizontal center vertices of two objects when you precisely align the vertices.