document.write( "Question 1199591: Im a triangle ABC.
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document.write( "Cos A/a = Cos B/b = Cos C/c, and a = 2. It is possible to compute the area of the
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document.write( "triangle, (Hint: compare the problem data with the Law of the Sines, compute ratios between the sines and cosines of the angles)
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document.write( "A) sqrt3/4
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document.write( "B) sqrt3/2
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document.write( "C) sqrt3
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Algebra.Com's Answer #833553 by math_tutor2020(3817)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "cos(A)/a = cos(B)/b = cos(C)/c \n" ); document.write( "cos(A)/a = cos(B)/b \n" ); document.write( "cos(A)/cos(B) = a/b\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use the law of sines to apply similar steps: \n" ); document.write( "sin(A)/a = sin(B)/b = sin(C)/c \n" ); document.write( "sin(A)/a = sin(B)/b \n" ); document.write( "sin(A)/sin(B) = a/b\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We can see that: \n" ); document.write( "cos(A)/cos(B) = a/b \n" ); document.write( "cos(A)/cos(B) = sin(A)/sin(B) \n" ); document.write( "which can be rearranged into \n" ); document.write( "sin(B)/cos(B) = sin(A)/cos(A) \n" ); document.write( "tan(B) = tan(A) \n" ); document.write( "B = A \n" ); document.write( "A = B\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Follow a similar chain of logic to conclude that B = C.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We have A = B and B = C, so A = C \n" ); document.write( "All three angles are the same measure. \n" ); document.write( "A+B+C = 180 \n" ); document.write( "A+A+A = 180 \n" ); document.write( "3A = 180 \n" ); document.write( "A = 180/3 \n" ); document.write( "A = 60 \n" ); document.write( "Each angle is 60 degrees. \n" ); document.write( "The triangle is equilateral.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Area of equilateral triangle with side length 's' \n" ); document.write( "Area = 0.25*s^2*sqrt(3) \n" ); document.write( "Area = 0.25*2^2*sqrt(3) \n" ); document.write( "Area = sqrt(3)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: C) sqrt(3) \n" ); document.write( " \n" ); document.write( " |