document.write( "Question 755371: Find the missing side and angles of triangle ABC \r
\n" ); document.write( "\n" ); document.write( "sides:
\n" ); document.write( "A= 12
\n" ); document.write( "B= 13
\n" ); document.write( "C= 17.69 \r
\n" ); document.write( "\n" ); document.write( "I had to find side C. So I took A^2 + B^2 = C^2 and put in 12^2 + 13^2 = C^2. 144+169=c^2. I added the left side and got 313 then I used the square root on both sides and got C = 17.69 \r
\n" ); document.write( "\n" ); document.write( "Angles:
\n" ); document.write( "A=
\n" ); document.write( "B=
\n" ); document.write( "C= 76 degrees \r
\n" ); document.write( "\n" ); document.write( "How do I find the missing angles? Is my side C correct? Thank you for the help!
\n" ); document.write( "

Algebra.Com's Answer #459673 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
Find the missing side and angles of triangle ABC
\n" ); document.write( "sides:
\n" ); document.write( "A= 12
\n" ); document.write( "B= 13
\n" ); document.write( "C= 17.69
\n" ); document.write( "I had to find side C. So I took A^2 + B^2 = C^2 and put in 12^2 + 13^2 = C^2. 144+169=c^2. I added the left side and got 313 then I used the square root on both sides and got C = 17.69
\n" ); document.write( "Angles:
\n" ); document.write( "A=
\n" ); document.write( "B=
\n" ); document.write( "C= 76 degrees
\n" ); document.write( "How do I find the missing angles? Is my side C correct?
\n" ); document.write( "--------------------------------------------------------------------
\n" ); document.write( "You have assumed this is a right triangle by using a^2 + b^2 = c^2
\n" ); document.write( "But it's not, in a right triangle, the hypotenuse (c) is opposite
\n" ); document.write( "the right angle (C) and here it is given as 76 degrees.
\n" ); document.write( ":
\n" ); document.write( "We have to use the law of cosines, which is:
\n" ); document.write( " c^2 = a^2 + b^2 -2(ab)*cos(C), in this problem
\n" ); document.write( "a=12, b=13, Angle C = 76; we will find side c:
\n" ); document.write( "c^2 = 12^2 + 13^2 - 2(12*13)*cos(76)
\n" ); document.write( "c^2 = 144 + 169 - 2(156)*.24192
\n" ); document.write( "c^2 = 313-75.48
\n" ); document.write( "c = \"sqrt%28237.52%29\"
\n" ); document.write( "c = 15.41 is side c
\n" ); document.write( ":
\n" ); document.write( "Use the law of sines to find Angle A
\n" ); document.write( "\"12%2Fsin%28A%29\" = \"15.41%2Fsin%2876%29\"
\n" ); document.write( "15.41*sin(A) = 12*sin(76)
\n" ); document.write( "sin(A) = \"11.6435%2F15.41\"
\n" ); document.write( "sin(A) .7556
\n" ); document.write( "A = 49.1 degrees
\n" ); document.write( "then
\n" ); document.write( "B = 180 - 76 - 49.1
\n" ); document.write( "B = 54.9 degrees
\n" ); document.write( ":
\n" ); document.write( "summarize
\n" ); document.write( "sides
\n" ); document.write( "a = 12
\n" ); document.write( "b = 13
\n" ); document.write( "c = 15.41
\n" ); document.write( "Angles
\n" ); document.write( "A = 49.1 degrees
\n" ); document.write( "B = 54.9
\n" ); document.write( "C = 76 degrees
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