Question 1103180
*[illustration fr5.png].
.
.
Use the law of sines,
{{{sin(80)/31=sin(b)/14}}}
{{{sin(b)=(14/31)sin(80)}}}
Solve for b.
Once you have b, solve for c.
{{{80+b+c=180}}}
{{{c=100-b}}}
Then use the law of sines again,
{{{sin(80)/31=sin(c)/AB}}}
{{{AB*sin(80)=31sin(c)}}}
{{{AB=31*(sin(c)/sin(80))}}}