For uppercase C, use the rule that angles in a triangle add up to 180.
#36+98+C=180#
#180-98-36=C#
#46=C#
Then, use the Law of Sines. Set up proportions :
#sin(A)/a=sin(B)/b=sin(C)/c#
Let's find side #a# first using C and c.
#a/sin(A)=c/sin(C)#
#a/sin(36)=18/sin(46)#
Multiply both sides by #sin(36)#
#a=18/sin(46)*sin(36)#
Get out your calculator.
#aapprox14.71 (2dp)#
Now, let's solve for #b#. It is better to use the #C# and #c# proportion than the previously attained #a# and #A# proportion because #a# is not 100% accurate, and if it was not correct, then we would lose a mark if we used the #A# and #a# proportion but not if you use the #C# and #c# proportion.
#b/sin(B)=c/sin(C)#
#b/sin(98)=18/sin(46)#
Multiply both sides by #sin(98)#
#b=18/sin(46)*sin(98)#
Get out your calculator.
#bapprox24.78 (2dp)#
