ANS:C - Both (a) and (b)

1. Discharge over a Triangular Notch (a): The discharge over a triangular notch is derived from the weir flow equation, which is proportional to the square root of the head (H^1/2) times the cube of the head (H^3), resulting in H^5/2. This relationship is based on the principles of fluid mechanics and geometry of the triangular notch.
2. Discharge over a Rectangular Notch (b): Similarly, the discharge over a rectangular notch is derived from the weir flow equation and is proportional to the square root of the head (H^1/2) times the head (H^2), resulting in H^3/2. This relationship is also based on fluid mechanics and the geometry of the rectangular notch.