Solution:

1) Select (single-click) the desired picture. (Handles appear around the picture.)
2) Select the 'Tools' menu and select 'Crop Picture'. (The cursor changes to a cropping tool.)
3) Position the center of the cropping tool on one of the picture's handles.
position tool
NOTE: The picture handles are the small squares that appear along the outline of the picture when it is selected. Place the open square area of the cropping tool over a handle.
4) Press and hold down the left mouse button.
5) Drag in the desired direction to select the area that will remain in the picture.
select area
NOTE: As the cursor is dragged across the picture, a dashed boundary line indicates the area that will remain in the picture. Areas of the picture that are NOT selected with the cropping tool will be cut.
6) Release the mouse button. (The picture is cropped.)
7) Click mouse button outside the picture to deactivate the cropping tool.