SOLUTION: In triangle DEF angle D= 112 degrees, e= 11 cm, and f=14 cm. Find the measure of side d. Thanks.

Algebra ->  Trigonometry-basics -> SOLUTION: In triangle DEF angle D= 112 degrees, e= 11 cm, and f=14 cm. Find the measure of side d. Thanks.      Log On


   

Question 972318: In triangle DEF angle D= 112 degrees, e= 11 cm, and f=14 cm. Find the measure of side d. Thanks.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Law of cosines
side d
d^2=e^2 +f^2-2ef cos 112
d^2=121 + 196 -2(154) cos 112 all units will be cm^2
d^2=317 -108 cos (112);; cos 112=-.3746
d^2=317 plus 40.46 ;; cos is negative so second term is positive
d^2=357.46
d=18.91 cm
This makes sense, because it is the side opposite the largest angle, so it should be larger.