Given C=106 degrees, a=4, and b=15, use the Law of Cosines to solve the triangle for the value of c. Round answer to two decimal places. (Draw a picture).

Question

Given C=106 degrees, a=4, and b=15, use the Law of Cosines to solve the triangle for the value of c. Round answer to two decimal places. (Draw a picture).

Answer 1

Cosine law in this case will be c^2 = a^2 +b^2 -2*a*b*cos; Cos C is negative and equal to -0.2756

plugging values in the equation, the solution will be:

c^2= 16 + 225 + 2*3*15*0.276 = 265.84

Then c equals 16.3