Calculate the values of a,A and C in ∆ABC,given that b=17.23 cm,c=10.86 cm and B=115°.using cosine rule

2 answers

Yes
you have to start with the sine rule, since B is not included between sides b and c.
sinC/c = sinB/b
Now you have B and C, so A=180-(B+C) and the cosine rule gives you a:
a^2 = b^2+c^2 - 2bc cosA