Use the Law of Cosines Solve the triangle given a 763 m c

Use the Law of Cosines. Solve the triangle given a = 76.3 m, c = 42.8 m and B = 16.3 degree.

Solution

b²=a²+c²-2accosB

b²=76.3²+42.8²-2*76.3*42.8cos16.3^o

b²=1384.773

b=37.2

cosA=(b²+c²-a²)_/2bc

cosA=(37.2²+42.8²-76.3²)_/2*37.2*42.8

cosA=-0.8183

A=144.9^o

cosC=(a²+b²-c²)_/2ab

cosC=(76.3²+37.2²-42.8²)_/2*76.3*37.2

C=18.8^o