Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 month ago

Find the length of GI in the triangle below. (Geometry Question)?

Can someone give a detailed explanation on how to find this answer? I'm having a lot of trouble with it, thank you!

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  • TomV
    Lv 7
    1 month ago
    Favorite Answer

    Use the Law of Cosines:

    c² = a² + b² - 2ab cosC

    where c is the side of the triangle opposite angle C

    In the given triangle, let

     a = GH =60

     b = HI = 42

     c = GI

     C = 123°

    c² = 60² + 42² - 2(60)(42) cos123° = 8108.9807...

    c ≈ 90.050

  • 1 month ago

    Cosine Law

    GI² = GH² + HI² - 2 GH HI cos ∠H

    GI = √(GH² + HI² - 2 GH HI cos ∠H)

    GI = √(60² + 42² - 2*60*42*cos 123°)

    GI = 90.05

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