document.write( "Question 755371: Find the missing side and angles of triangle ABC \r
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document.write( "sides:
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document.write( "A= 12
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document.write( "B= 13
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document.write( "C= 17.69 \r
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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
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document.write( "Angles:
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document.write( "B=
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document.write( "C= 76 degrees \r
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document.write( "How do I find the missing angles? Is my side C correct? Thank you for the help! \n" );
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Algebra.Com's Answer #459673 by ankor@dixie-net.com(22740)![]() ![]() 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 = \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( " \n" ); document.write( "15.41*sin(A) = 12*sin(76) \n" ); document.write( "sin(A) = \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 \n" ); document.write( " \n" ); document.write( " |