The study looked at different shapes of piano key weirs to see how well they work. Triangular weirs had the best flow, followed by trapezoidal and then rectangular weirs. The triangular weir had 28.2% better flow than the rectangular one, and the trapezoidal weir had 12.9% better flow. All three types of piano key weirs had much better flow than a regular sharp crest weir. The equations used to calculate the flow were very accurate, with only small errors.