Make a selection with the practice image to get the results shown on the left. (I used the magnetic lasso tool to make a quick selection.) To the right is a screen shot of the image after choosing Image > Crop.
For more on cropping, see these articles:
- Straighten a Crooked Image with the Crop Tool in Photoshop or Elements
- Two Ways to Straighten a Skewed Horizon in your Photos
Fixing Problems with Photoshop's Crop
- Tool


