Weird. And just so we are on the same page, your emulator is actually rotating when you press the rotate button? You should see a landscape layout for GeoQuiz.
I did personally have an issue where the emulator was unresponsive after rotating it. It has been fixed in beta versions of Android Studio, but you can get a temporary workaround by having it open in a separate window (See: Android Studio Emulator in a Separate Window - Stack Overflow).