Use drag controls to resize an element.
Drag controls display at the ends of selected elements in plan views. They also display along the ends, bottoms, and tops of selected elements in elevation and 3D views, where they are labeled as shape handles. Drag these controls to resize an element.
When a chain of walls or lines is selected, drag controls display at the coincident endpoints. Drag the controls to change the layout of the chain. See Select Chains of Walls and Lines.
Revit uses the following types of drag controls:
- Dots (
) display when movement is constrained to a plane, as with walls and lines in plan views. Drag a dot control to lengthen, shorten, or change the orientation of the element. 
Drag controls (shown in blue) on a wall in plan
- Single arrows (
) display as shape handles in elevation and 3D views when movement is constrained to a line, but the outside direction is unambiguous. For example, a 3D form with no dimension constraints displays with single arrows. Single arrow controls on a selected wall in 3D views can also be used to move the wall. Place the cursor over the control and press Tab to be able to move the wall without resizing it. 
Drag controls on a 3D form
- Double arrows (
) display when the shape handles are constrained to move along a line. For example, if you add a labeled dimension to a family and make it an instance parameter, it displays with a double arrow after you load it into a project and select it.
Tip: You can right-click the wall end controls and use an option on the context menu to allow or disallow wall joins.