8625 pointsLarPreCalcRMRPAlt6 72018My Notes Use the Law of C

8.–/6.25 pointsLarPreCalcRMRPAlt6 7.2.018.My Notes

Use the Law of Cosines to solve the triangle. (Round your answers to two decimal places.)

a= 47, b = 39, c = 66

A =

B =

C =

Solution

cosA=(b²+c²-a²)/(2bc)

cosA=(39²+66²-47²)/(2*39*66)

cosA=0.7125

A=44.56^o

cosB=(a²+c²-b²)/(2ac)

cosB=(47²+66²-39²)/(2*47*66)

cosB=0.813

B=35.61^o

cosC=(a²+b²-c²)/(2ab)

cosC=(47²+39²-66²)/(2*47*39)

cosC=-0.1708

C=99.83^o