Question 963753
From the area, assume that the base is 18, then,
{{{(1/2)18h=85}}}
{{{h=170/18}}}
The angle, A, opposite the unknown side, a, can be determined using side 11 and h since,
{{{sin(A)=h/11=170/198}}}
{{{A=59.158}}}
So then  using the law of cosines,
{{{a^2=11^2+18^2-2(11)(18)cos(59.158)}}}
{{{a^2=121+324-203.018}}}
{{{a^2=241.982}}}
{{{highlight(a=15.56)}}}