I don't understand about NDK_ROOT path in tutiorial

Hello. I am return cocos2d-x
Thanks God.

Anyway. I found in wiki
That’s a http://www.cocos2d-x.org/projects/cocos2d-x/wiki/Setting_up_Android_Development_Environment_on_Mac_OSX

export ANDROID_NDK_ROOT="/Users/iven/Dev/android/Users/iven/Dev/Android/adt-bundle-mac-x86_64/sdk

Hm… I just figure out why NDK_ROOT path is SDK.

Please anybody say about it.
Thank you.