The official documentation only says the built-in Extended type is 10 bytes on Win32 platform and 8 bytes on Win64 platform (Alias of Double).

The official documentation only says the built-in Extended type is 10 bytes on Win32 platform and 8 bytes on Win64 platform (Alias of Double).  

But What's the size of the Extended type in the other platforms? (OSX, IOSARM, IOS32, ANDROID)?

http://docwiki.embarcadero.com/Libraries/XE6/en/System.Extended
http://docwiki.embarcadero.com/Libraries/XE6/en/System.Extended