Cannot resolve class RelativeLayout

The error message "Cannot resolve class RelativeLayout" usually occurs when there is an issue with importing the necessary class in your code.

RelativeLayout is a class that is part of the Android framework and is used to create complex layouts in Android applications. In order to use it, you need to import the class by adding the following line of code at the top of your Java file:

import android.widget.RelativeLayout;

If you have already imported this class and are still getting the error message, make sure that you have the necessary Android SDK installed and that your project is set up correctly. You can also try cleaning and rebuilding your project to see if that resolves the issue.