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Section C — Calculations (show work) (6–8 points each) 10. A trapezoidal channel has bottom width b = 4 m, side slopes 1H:1V, and depth of flow y = 2 m. Compute: a) Cross-sectional area A. b) Wetted perimeter P. c) Hydraulic radius R. (Use geometry; g = 9.81 m/s^2 only if needed.) open channel hydraulics ven te chow solution manual pdf