SOLUTION: Two sides and a diagonal of a parallelogram are 7,9 and 15 in respectively. Find the measures of the angles of the parallelogram?

Question 1080903: Two sides and a diagonal of a parallelogram are 7,9 and 15 in respectively. Find the measures of the angles of the parallelogram?
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
If I draw the parallelogram and have side with length 7 be a and side 9 b, and diagonal 15 be c, I can use the law of cosines.
c^2=a^2+b^2-2ab cos C
225=49+81-2*7*9*( cos C)
95=-126 cos C
cos C=-95/126
C=138.94 degrees, and the opposite angle would be the same. The adjacent angles are supplementary and would be 41.06 degrees.

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