Straighten Up with Perspective Crop
Open the photo Sign.jpg. This photo was taken at an angle. It can be difficult to read. Select the Perspective Warp Tool. Click on each corner of the image. A grid will appear over the image. You may not be able to see all four corners on an image. If this is the case, place a corner where you estimate it would be.
Make sure that all of your bounding lines line up with the border of the image.
Once you have adjusted your grid, press Enter/Return to apply the crop. You will see that the corner area of the sign is filled with the background color. From here, you could use the Clone Stamp to fill this area with the beige of the sign. This type of Crop option does not come with Content Aware.
Practice on your own:
Open the PerspectiveCrop.jpg from your source folder. Repeat the steps above to see if you can make a straight row of paintings.