Steady$-$state $2-$D Heat Conduction in a Rectangular Sheet Determine the steady$-$state temperature distribution in a rectangular plate A$(0,0),$ B$(0,6),$ C$(10,6),$ D$(10,0)$ if the temperature along AB$,$ BC$,$ and AD are maintained at zero temperature while the edge CD is at temperature $80\backslash$deg $.$ B u$=0\backslash$deg $$ nity u$($x$,$y$)=$ E Bn sinh nx$.$ sin $66$ n$=1160(1-$os nt $)$ Bn $\backslash$Sigma $\backslash$epsi U $=0\backslash$deg u $=80\backslash$deg TT sinh an $30$ D $10$ u$=0\backslash$deg X