#includeIn this example, we create a QRect object with width 5 and height 10. We then call the transpose() method, which exchanges the width and height values of the object. The resulting object will have a width of 10 and a height of 5. Package Library: The QSize class is part of the Qt Core module, which is included in the Qt framework. Therefore, in order to use the QSize class and the transpose() method, the Qt framework needs to be installed and linked to the project.QSize mySize(5, 10); mySize.transpose(); // After transpose, mySize.width() will be 10 and mySize.height() will be 5.