The reason why your android phone is stuck or hanging, may be as a result of some app installed on the phone is not functioning correctly. However resetting the phone will solve this problem.
This is how you can get your android phone reset to the original factory functioning.
1. Go the settings section of your phone, by clicking on the setting icon.
2. Now scroll down and click on the Backup & Reset tap. Note, on some Android phone you see General Management , click on it and then select Reset.
3. Once that is done, you will be prompted with another screen, here click on the Factory Data Reset, which is located at the bottom of the menu.
4. Finally click on the RESET phone and the reset process will begin. As soon as it is completed, your phone will return to the factory settings that it came with, meaning it has been restored to its original form.
That's all, you may need to backup your pictures, but not to worry if you cant, most android phone now do autobackup to google photos.