Clear the board by collecting 3 matching shapes. When you make a set of 3 same shapes, they get cleared.
Tap a shape to pick it. The picked shape goes into your pick/holding slots at the top (the small empty circles).
Make a triple: If you collect 3 of the same shape in your slots, they clear automatically.
Don’t fill the slots: Your pick area/slots are limited, so the order you pick shapes matters.