I was wondering if someone could check my work I am not getting the same answer that is in the back of the book. The question is to find the area of a parallelogram if the two sides measure 8.4 inches and 3.4 inches and one angle measures 135 degrees.

I tried using both the pythagorean theorem and the law of cosines and still couldn't come up with the correct answer, but the answer key in the book has been known to have typo's.

I'd appreciate any help, thanks