Anonymous
Anonymous asked in Science & MathematicsMathematics · 5 days ago

PreCalc Need Help?

Suppose you need to find the height of a tall building. Standing 15 meters away from the base of the building, you aim a laser pointer at the closest part of the top of the building. You measure that the laser pointer is 7◦ 

tilted from pointing straight up. The laser pointer is held 2 meters above the ground. How tall is the building?

3 Answers

Relevance
  • 5 days ago

    Refer to the figure below.

    Point A is the laser pointer, and point B is the closest part of the top of the building.

    In ΔABC:

    tan(∠BAC) = BC/AC

    tan(90° - 7°) = BC/(15 m)

    BC = 15 tan(83°) m

    BC = 122 m

    Height of the building

    = (122 + 2) m

    = 124 m

    Attachment image
  • Jim
    Lv 7
    5 days ago

    SOHCAHTOA so you want Tan

    Tan 83 = Opp/15; Opp = 15 Tan 83 = 122.1651

    Then add 2 m = 124 m

  • 5 days ago

    tan 7 = 15 / h

    h = 15 / tan 7 = 122 m

    add 2 to get 124 m

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