Aim first yellow bird at lower thin wood supports of closest tower. The key to getting a high score is to get tower to topple to the right and take out second tower.
Aim second floppy bird to take out base of third tower.
I find much easier if the yellow bird hit the horizontal stone bar at the top of first tower, the triangle stone will fall to the right tower & hit the sandbox to destabilize first tower.
I find much easier if the yellow bird hit the horizontal stone bar at the top of first tower, the triangle stone will fall to the right tower & hit the sandbox to destabilize first tower.