Find the length of the side AB in the triangle ∆ABC in the ﬁgure

Question

anonymous · Answer

attachment

mertsj · Answer

sin122/10 = sinB/5   Angle B = 25 degrees so Angle C = 180-25-122=33 degrees.
Now use the law of cosines:  c^2 = a^2+b^2-2abcosC
                                          c^2=100+25-2(10)(5)cos33
                                           c^2 = 125 -100(.8387)
                                           c^2 = 125 - 83.87
                                            c^2=41.13
                                                c=6.41