The cross$-$section of a rough, rectangular, concrete $($k $=0\mathrm{.}2$ X $10^-2$ ft$)$ channel measures $6$x$6$ ft$.$ The channel slope is $0\mathrm{.}02$ ft$/$ft$.$ Using the Manning's equation, determine the maximum allowable flow rate through the channel to maintain one foot of freeboard $($freeboard is the vertical distance from the water surface to the overtopping level of the channel$).$ Assume water is $20$ degrees Celsius. For these conditions, find the following characteristics.

A$.$ Flow area

B$.$ Wetter perimeter

C$.$ Hydraulic radius

D$.$ Velocity

E$.$ Froude number