If you have taken a photo with your Samsung Galaxy S9, it may be upside down or tilted to either side. However, you will want to rotate the photo so that it appears correctly on the Samsung Galaxy S9 display.
If you do not yet know how to do this, the following article should show you how to do this:
Rotate images on the Samsung Galaxy S9 afterwards
1. Open the gallery app on the Samsung Galaxy S9
2. Touch the photo you want to rotate
3. Touch the square with the arrow at the bottom left of the row of icons - this will open the editor
4. Touch the rotated arrow icon again - each time you touch the icon, the photo will rotate 90° clockwise
You now just need to save the rotated photo. To do this, press the "Save" button in the upper right corner. You now know how to rotate a photo 90° with the Samsung Galaxy S9. However, you can also rotate the photo by individual degrees.
To do this, use the slider in the middle. Move it to the right or left to set an exact degree of inclination.