CH7 A This problem refers to triangle ABC If a 130 inches b

CH7

A)

This problem refers to triangle ABC. If a 130 inches, b 58 inches, and C 60 find c. (Round your answer to the nearest whole number.) In

Solution

a. largest angle is opposite to longest side which is c

and we use cosine law here which is

c^2= a^2 + b^2 -2ab cos C

14^2= 12^2 + 13^2 -2(12)(13) cos C

196= 144 +169 -312 cos C

117=312cos C

C=68 degree

b. b^2=a^2 + c^2 -2ac cos B

         = 3.9^2 + 6.8^2 -2(3.9)(6.8)cos23

         =61.45- 53.04cos23

      b^2=12.6264

b=3.6