This is quite a unique mahjong layout. The triangle is not too difficult since there are a lot of open tiles when you've removed the few stones on the top. If you really don't see any more moves, the game even includes hints.
The game feels like it's going a bit slow since it takes a short moment before matched tiles disappear from the stage.
Play the game Triangle Mahjong and more mahjong games on King of Mahjong. There are a lot of varieties build with the classic board game as starting point. In a computer game the options are limitless and you won't have to clean up the stones after playing!