SDK location not found. Define location with an ANDROID_SDK_ROOT environment variable or by setting the sdk.dir path in your project’s local properties file

Error while building the Android Project:

SDK location not found. Define location with an 
ANDROID_SDK_ROOT environment variable or by setting the 
sdk.dir path in your project's local properties file at 
.../local.properties.

Solution is to create a file named local.properties at the root of your Android project. If you are or on MAC or Ubuntu you can use the following command to create that:

touch local.properties

Enter the following text in that file:

sdk.dir = /Users/<yourusername>/Library/Android/sdk

Example:

sdk.dir = /Users/johnsmith/Library/Android/sdk

The above example was for MAC, for Ubuntu it would be:

sdk.dir = /home/<UserName>/Android/Sdk

and for Windows it would be:

C:\\Users\\<YourUserName>\\AppData\\Local\\Android\\sdk

Save the file and rebuild the Android project and it should work now.