to find angle a we do 180-(62+48)=180-110=70 angle a =70 with this we can use the sin rule a/sin(A)=b/sin(B)=c/sin(C) since we have side a and angle A and angle b we can do: 18.2/sin(70)=b/sin(62) then we can times by sin(62) (18.2/sin(70))*sin(62)=17.1