Solve the triangle b4 c 7 A 140 Do not round until the fin

Solve the triangle. b=4, c = 7, A = 140 (Do not round until the final answer. Then round to the nearest tenth as needed.) (Do not round until the final answer. Then round to the nearest degree as needed.) (Do not round until the final answer. Then round to the nearest degree as needed.)

Solution

b = 4 , c = 7 , A = 140

applying law of cosines to find a

a^2 = b^2 + c^2 - 2 bc cos A

a^2 = 4^2 + 7^2 - 2(4)(7) cos 140

a = 10.4

applying law of sines to find B

b / sin B = a / sin A

4 / sin B = 10.4 / sin 140

B = 14 degrees

C = 180 - ( 14 + 140 )

C = 26 degrees