Given a= 108 degree, b=9 and c = 15, use the law of cosines to solve the triangle for the value of a. round answer two decimal places.
a. 19.13
b. 14.92
c. 19.73
d. 18.53

Find the value of a. the diagram is not to scale. a quadrilateral is drawn. the upper and lower sides are parallel. the interior angle in the upper left corner is labeled a degrees. the angle in the upper right corner is labeled 113 degrees. the angle in the lower right corner is labeled b degrees. the angle in the lower left corner is labeled 36 degrees. a. 36 b. 144 c. 54 d. 126

If the value of cos330°is√3/2 then find cos 165°.

What is the answer to the question 5x+2x