document.write( "Question 1179789: 300 ft from the base of a mountain the top and the base of a tower on its summit is sighted @ 27degree 43’ & 24degree 25’ respectively. At the base of the mountain the angles of elevation are 39degree & 35degree respectively. Find the height of the tower? \n" ); document.write( "
Algebra.Com's Answer #850174 by CPhill(1987) You can put this solution on YOUR website! Let's break down this problem step-by-step using trigonometry.\r \n" ); document.write( "\n" ); document.write( "**1. Diagram:**\r \n" ); document.write( "\n" ); document.write( "* Draw a horizontal line representing the ground. \n" ); document.write( "* Mark a point A on the ground, 300 ft from the base of the mountain. \n" ); document.write( "* Draw a vertical line representing the mountain. Let the base of the mountain be B and the top be C. \n" ); document.write( "* Draw a tower on top of the mountain. Let the top of the tower be D. \n" ); document.write( "* From point A, draw lines to B, C, and D. \n" ); document.write( "* Draw a vertical line from the base of the mountain (B) to the top of the mountain (C). Also draw a vertical line from the base of the mountain to the top of the tower (D).\r \n" ); document.write( "\n" ); document.write( "**2. Given Information:**\r \n" ); document.write( "\n" ); document.write( "* Distance from A to the base of the mountain (AB) = 300 ft \n" ); document.write( "* Angle of elevation from A to the base of the tower (∠BAB) = 24°25' \n" ); document.write( "* Angle of elevation from A to the top of the tower (∠BAD) = 27°43' \n" ); document.write( "* Angle of elevation from B to the base of the tower (∠EBC) = 35° \n" ); document.write( "* Angle of elevation from B to the top of the tower (∠EBD) = 39° where E is a point on the horizontal line drawn from A to the base of the mountain.\r \n" ); document.write( "\n" ); document.write( "**3. Convert Angles to Decimal Degrees:**\r \n" ); document.write( "\n" ); document.write( "* 24°25' = 24 + 25/60 ≈ 24.4167° \n" ); document.write( "* 27°43' = 27 + 43/60 ≈ 27.7167° \n" ); document.write( "* 35° \n" ); document.write( "* 39°\r \n" ); document.write( "\n" ); document.write( "**4. Calculate the Height of the Mountain (BC):**\r \n" ); document.write( "\n" ); document.write( "* In triangle ABC, tan(24.4167°) = BC / AB \n" ); document.write( "* BC = AB * tan(24.4167°) \n" ); document.write( "* BC = 300 * tan(24.4167°) \n" ); document.write( "* BC ≈ 300 * 0.4539 \n" ); document.write( "* BC ≈ 136.17 ft\r \n" ); document.write( "\n" ); document.write( "**5. Calculate the Height of the Mountain Plus Tower (BD):**\r \n" ); document.write( "\n" ); document.write( "* In triangle ABD, tan(27.7167°) = BD / AB \n" ); document.write( "* BD = AB * tan(27.7167°) \n" ); document.write( "* BD = 300 * tan(27.7167°) \n" ); document.write( "* BD ≈ 300 * 0.5244 \n" ); document.write( "* BD ≈ 157.32 ft\r \n" ); document.write( "\n" ); document.write( "**6. Calculate the Height of the Tower (CD):**\r \n" ); document.write( "\n" ); document.write( "* CD = BD - BC \n" ); document.write( "* CD = 157.32 - 136.17 \n" ); document.write( "* CD ≈ 21.15 ft\r \n" ); document.write( "\n" ); document.write( "**7. Calculate the height of the mountain using the angles of elevation at B:**\r \n" ); document.write( "\n" ); document.write( "* Let the height of the mountain be h. \n" ); document.write( "* tan(35°) = h/ distance from B to a point on the horizontal line from A. \n" ); document.write( "* Let the distance from B to a point on the horizontal line be x. \n" ); document.write( "* tan(39°) = (h+tower)/x. \n" ); document.write( "* tan(35°) = h/x \n" ); document.write( "* x = h/tan(35°) \n" ); document.write( "* tan(39°) = (h+tower)/(h/tan(35°)) \n" ); document.write( "* tan(39°) = (h+tower)*tan(35°)/h \n" ); document.write( "* h*tan(39°) = h*tan(35°) + tower*tan(35°) \n" ); document.write( "* h(tan(39°)-tan(35°)) = tower*tan(35°) \n" ); document.write( "* tower = h(tan(39°)-tan(35°))/tan(35°) \n" ); document.write( "* tower = h(0.8098-0.7002)/0.7002 \n" ); document.write( "* tower = h(0.1096)/0.7002 \n" ); document.write( "* tower = 0.1565h.\r \n" ); document.write( "\n" ); document.write( "**8. Calculate the height of the mountain using the first set of angles:**\r \n" ); document.write( "\n" ); document.write( "* BC = 136.17 ft.\r \n" ); document.write( "\n" ); document.write( "**9. Calculate the height of the tower using the first set of angles:**\r \n" ); document.write( "\n" ); document.write( "* CD = 21.15 ft.\r \n" ); document.write( "\n" ); document.write( "**10. Substitute BC into the equation for the tower:**\r \n" ); document.write( "\n" ); document.write( "* tower = 0.1565*136.17 \n" ); document.write( "* tower = 21.3193\r \n" ); document.write( "\n" ); document.write( "**Answer:**\r \n" ); document.write( "\n" ); document.write( "The height of the tower is approximately 21.15 feet. \n" ); document.write( " \n" ); document.write( " |