SOLUTION: The lengths of two adjacent sides of a parallelogram are 42cm and 36cm. An angle of the parallelogram is 40degrees. Find the measure of the longest diagonal to the nearest tenth of

Algebra ->  Trigonometry-basics -> SOLUTION: The lengths of two adjacent sides of a parallelogram are 42cm and 36cm. An angle of the parallelogram is 40degrees. Find the measure of the longest diagonal to the nearest tenth of      Log On


   



Question 455481: The lengths of two adjacent sides of a parallelogram are 42cm and 36cm. An angle of the parallelogram is 40degrees. Find the measure of the longest diagonal to the nearest tenth of a centimeter. (do you use the law of cosine?)
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The lengths of two adjacent sides of a parallelogram are 42cm and 36cm. An angle of the parallelogram is 40 degrees. Find the measure of the longest diagonal to the nearest tenth of a centimeter. (do you use the law of cosines?)
-------------
Draw the picture and you will see that the longest diagonal is opposite
the adjacent angle in the parallelogram, which is 140 degrees.
--------------------------
diag^2 = 42^2 + 36^2 - 2^42*36*cos(140)
diag = 73.32
==================
Cheers,
Stan H.