If you've unintentionally taken a photo at an angle, you can use the Straighten tool to adjust and correct it.
Do any of the following:
Straighten the photo automatically: Tap Auto in the Straighten tool options.
Straighten manually: Use the tilt wheel to choose a precise angle at which you want to tilt your photo.
Choose the Crop tool by doing any of the following:
Press C on your keyboard.
If a different crop mode is selected, tap the crop mode button and choose Straighten.
Do any of the following:
Straighten the photo automatically: Tap Auto in the Straighten tool options.
Straighten manually: Use the tilt wheel to choose a precise angle at which you want to tilt your photo.
Choose the Crop tool by doing any of the following:
Choose Tools > Crop from the Tools menu at the top of your screen.
Press C on your keyboard.
Do any of the following:
Straighten manually: Drag the Straighten slider to choose the angle at which you want to straighten the image. You can also click the buttons at each end of the slider or click the value field to enter a precise angle from –45° to 45°.