It may be noted that the analysis and conclusions obtained below

are valid for all sections of a channel with divergent walls

$($sections$,$ triangular, trapezoidal, parabolic etc.$),$ a$).$ Using the equation of

hydraulic radius in a trapezoidal channel find the equation corresponding to

$/$ and b$).$ With this equation show that $/$ is always less than one

and always decreases with increasing flow depth $($y$)$ when $0<=\backslash$theta $<90\backslash$deg $,$

$0<=$ k $<\backslash$infty $,$ k $<21+^2.$