Select an object by single-clicking it. When an object is selected, its border becomes visible along with eight resizing handles.
Clicking and dragging a resize handle will resize the object in the appropriate direction. Holding down the Shift button while resizing maintains the object's current aspect ratio. Note: The opposite is true for Picture and Movie objects. Dragging the resize handle for those particular objects will maintain the aspect ratio, while holding down Shift while dragging the handle will resize the object to your liking.