document.write( "Question 1170415: a man sitting on 22.5 m high storey building measures the angles of elevation of a telecom mast directly ahead of him as 43°. He measures the angle of elevation of the mast when he is 52m in the front of the building on the horizontal ground as 70°
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document.write( "A calculate the height of the mast
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document.write( "The distance between the building and the mast. \n" );
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Algebra.Com's Answer #851191 by CPhill(1959)![]() ![]() You can put this solution on YOUR website! Let's break down this problem step-by-step.\r \n" ); document.write( "\n" ); document.write( "**Diagram:**\r \n" ); document.write( "\n" ); document.write( "Imagine the following:\r \n" ); document.write( "\n" ); document.write( "* **B:** The base of the building. \n" ); document.write( "* **T:** The top of the building. \n" ); document.write( "* **M:** The top of the telecom mast. \n" ); document.write( "* **H:** The base of the telecom mast. \n" ); document.write( "* **P1:** The man's first position on the building. \n" ); document.write( "* **P2:** The man's second position on the ground.\r \n" ); document.write( "\n" ); document.write( "**Given:**\r \n" ); document.write( "\n" ); document.write( "* Building height (BT) = 22.5 m \n" ); document.write( "* Angle of elevation from P1 to M = 43° \n" ); document.write( "* Distance P2B = 52m \n" ); document.write( "* Angle of elevation from P2 to M = 70°\r \n" ); document.write( "\n" ); document.write( "**Let's define:**\r \n" ); document.write( "\n" ); document.write( "* Height of the mast (HM) = h \n" ); document.write( "* Distance between the building and the mast (BH) = x\r \n" ); document.write( "\n" ); document.write( "**Step 1: Analyzing the first position (P1)**\r \n" ); document.write( "\n" ); document.write( "* The man is on the top of the building, so TP1 is horizontal. \n" ); document.write( "* Let's draw a horizontal line from T to a point on HM, let's call it A. \n" ); document.write( "* Then, TA = BH = x, and AM = h - 22.5. \n" ); document.write( "* In triangle TAM, we have: \n" ); document.write( " * tan(43°) = AM / TA = (h - 22.5) / x \n" ); document.write( " * x = (h - 22.5) / tan(43°)\r \n" ); document.write( "\n" ); document.write( "**Step 2: Analyzing the second position (P2)**\r \n" ); document.write( "\n" ); document.write( "* In triangle HMP2, we have: \n" ); document.write( " * tan(70°) = HM / HP2 = h / x \n" ); document.write( " * x = h / tan(70°)\r \n" ); document.write( "\n" ); document.write( "**Step 3: Equating the two expressions for x**\r \n" ); document.write( "\n" ); document.write( "* Since both expressions equal x, we can set them equal to each other: \n" ); document.write( " * (h - 22.5) / tan(43°) = h / tan(70°) \n" ); document.write( " * (h - 22.5) * tan(70°) = h * tan(43°) \n" ); document.write( " * h * tan(70°) - 22.5 * tan(70°) = h * tan(43°) \n" ); document.write( " * h * tan(70°) - h * tan(43°) = 22.5 * tan(70°) \n" ); document.write( " * h (tan(70°) - tan(43°)) = 22.5 * tan(70°) \n" ); document.write( " * h = (22.5 * tan(70°)) / (tan(70°) - tan(43°))\r \n" ); document.write( "\n" ); document.write( "**Step 4: Calculating h (height of the mast)**\r \n" ); document.write( "\n" ); document.write( "* tan(70°) ≈ 2.7475 \n" ); document.write( "* tan(43°) ≈ 0.9325 \n" ); document.write( "* h = (22.5 * 2.7475) / (2.7475 - 0.9325) \n" ); document.write( "* h = 61.81875 / 1.815 \n" ); document.write( "* h ≈ 34.06 m\r \n" ); document.write( "\n" ); document.write( "**Step 5: Calculating x (distance between the building and the mast)**\r \n" ); document.write( "\n" ); document.write( "* x = h / tan(70°) \n" ); document.write( "* x = 34.06 / 2.7475 \n" ); document.write( "* x ≈ 12.40 m\r \n" ); document.write( "\n" ); document.write( "**Therefore:**\r \n" ); document.write( "\n" ); document.write( "* The height of the mast is approximately 34.06 meters. \n" ); document.write( "* The distance between the building and the mast is approximately 12.40 meters. \n" ); document.write( " \n" ); document.write( " |