document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1080903>Question 1080903</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two sides and a diagonal of a parallelogram are 7,9 and 15 in respectively. Find the measures of the angles of the parallelogram? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #694986 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=694986\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 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.<BR>\n" );
document.write( "c^2=a^2+b^2-2ab cos C<BR>\n" );
document.write( "225=49+81-2*7*9*( cos C)<BR>\n" );
document.write( "95=-126 cos C<BR>\n" );
document.write( "cos C=-95/126<BR>\n" );
document.write( "C=138.94 degrees, and the opposite angle would be the same.  The adjacent angles are supplementary and would be 41.06 degrees.\r<BR>\n" );
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