Bethany used the steps below in an attempt to solve for angle B in triangle ABC. 4.1 cm 2.7 cm 4.5 cm [Not drawn to

Question

Bethany used the steps below in an attempt to solve for angle B in triangle ABC.
4.1 cm
2.7 cm
4.5 cm
[Not drawn to scale]
4.12 – 4.52+2.72 -2(4.5)(2.7)cos B
4.1=4.5+2.7-24.3cos B
-3.1–24 3cOSB
0.1276= COS B

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Kaylee 1 month 2021-10-15T16:56:55+00:00 1 Answer 0 views 0

Answers ( )

    0
    2021-10-15T16:57:56+00:00

    Given that,

    The area parameters are

    A = 2.7 cm, B = 4.1 cm C = 4.5 cm

    We want to find the angle extended by B.

    Using cosine Rule

    b² = a² + c² – 2ac•Cosθ

    4.1² = 2.7² + 4.5² – 2 × 2.7 × 4.5• Cosθ

    16.81 = 7.29 + 20.25 – 24.3•Cosθ

    16.81 – 7.29 – 20.25 = -24.3•Cosθ

    -10.73 = -24.3•Cosθ

    Cosθ = -10.73 / -24.3

    Cosθ = 0.4416

    θ = Cos~1 (0.4416)

    θ = 63.8°

    The angle B is 63.8°

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45:7+7-4:2-5:5*4+35:2 =? ( )