The equation for circular conduits is:

$4x^2+44\mathrm{.}4y^2=D^2$

for rectangular conduits is:

$x^2+10\mathrm{.}4y^2=D^2$

$D$ is the diameter of a circular conduit or the width or height of a rectangular conduit, depending on

whether the side or top and bottom curves are being considered.

Example: the sluiceway for a dam discharge $80\frac{m^3}{s},$ if the coefficient of discharge from sluiceway is

$0\mathrm{.}9,$ and the head above the entrance is $60m,$ determine the profile of the entrance if:

Circular conduit was used,

Rectangular conduit was used.