geometry

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in a triangle DEF m<E is three times m<,and m <F is 9 less than m< E

  • geometry -

    D = X deg.
    E = 3X,
    F = 3X - 9.

    X + 3X + (3X - 9) = 180deg.
    7X = 180 + 9,
    7X = 189,
    X = 189 / 7 = 27deg.

    D = X = 27deg.
    E = 3X = 3*27 = 81deg.
    F = 3X - 9 = 3*27 - 9 = 72deg.

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