document.write( "Question 1198040: From a point A on level ground, the angle of elevation to the top of a tree is 38 degrees.
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document.write( "From point B that is 46 feet farther from the tree, the angle of elevation is 22 degrees. What is the height of the tree?\r
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document.write( "One of the possible answers are below:
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document.write( "A) 34.1 feet
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document.write( "B) 35.8 feet
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document.write( "C) 36.7 feet
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document.write( "D) 37.2 feet
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document.write( "E) 38.5 feet \n" );
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Algebra.Com's Answer #831552 by math_tutor2020(3817)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Here's a slight alternative approach to what the tutor Edwin McCravy has written. \n" ); document.write( "I'll be using his diagram and the notation he set up of u = tan(38), v = tan(22)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The slight different approach is to let \n" ); document.write( "BG = x \n" ); document.write( "BA = 46 \n" ); document.write( "AG = x-46\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "tan(angle) = opposite/adjacent \n" ); document.write( "tan(angle TBG) = TG/BG \n" ); document.write( "tan(22) = y/x \n" ); document.write( "y = x*tan(22)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "tan(38) = y/(x-46) \n" ); document.write( "tan(38) = x*tan(22)/(x-46) .... plug in y = x*tan(22) \n" ); document.write( "u = x*v/(x-46) .... make replacements for u and v \n" ); document.write( "u(x-46) = xv \n" ); document.write( "ux - 46u = xv \n" ); document.write( "ux-xv = 46u \n" ); document.write( "x(u-v) = 46u \n" ); document.write( "x = 46u/(u-v) \n" ); document.write( "x = 46*tan(38)/(tan(38)-tan(22)) \n" ); document.write( "x = 95.263733005284, which is the approximate length of segment BG.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = x*tan(22) \n" ); document.write( "y = 95.263733005284*tan(22) \n" ); document.write( "y = 38.489046505093 \n" ); document.write( "y = 38.5, which is the approximate length of segment TG.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: E) 38.5 feet\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Yet another approach\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Refer to the diagram Edwin McCravy has drawn.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Angle TAG = 38 degrees. \n" ); document.write( "angle TAB = 180-angle TAG = 180-38 = 142 degrees \n" ); document.write( "This is angle A of triangle TAB.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Focus on triangle TAB \n" ); document.write( "The interior angles T, A, B must add to 180 degrees. \n" ); document.write( "T + A + B = 180 \n" ); document.write( "T + 142 + 22 = 180 \n" ); document.write( "T + 164 = 180 \n" ); document.write( "T = 180 - 164 \n" ); document.write( "T = 16\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use the law of sines to find side 'a' which is opposite angle A.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sin(A)/a = sin(T)/t \n" ); document.write( "sin(142)/a = sin(16)/46 \n" ); document.write( "46*sin(142) = a*sin(16) \n" ); document.write( "a = 46*sin(142)/sin(16) \n" ); document.write( "a = 102.74524576336 \n" ); document.write( "This is the approximate length of segment TB.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then focus on triangle TBG to say the following: \n" ); document.write( "sin(angle) = opposite/hypotenuse \n" ); document.write( "sin(angle TBG) = TG/TB \n" ); document.write( "sin(22) = y/102.74524576336 \n" ); document.write( "y = 102.74524576336*sin(22) \n" ); document.write( "y = 38.489046505093 \n" ); document.write( "y = 38.5\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: E) 38.5 feet \n" ); document.write( " \n" ); document.write( " |