Plz help me, i dont kwnow what does this error mean

please help me to solve this problem… i spend 2days but i can not solved.

Does your Environment Variables - User Variables contain ANDROID_SDK_ROOT or ANDROID_HOME?

yes i already set the variables!

Probably follow Gradle setup details provided in the following link.
Ionic Link
Gradle link

follow the link for ionic-android environment setup - http://www.tiagoporto.com/blog/environment-setting-tutorial-ionic-android-on-windows/