A triangle has side lengths of 9 in, 13 in, and 20 in. What is the measurement of this triangle’s largest angle? 29.9° 129.9° 136.2° 50.1°.

Question

A triangle has side lengths of 9 in, 13 in, and 20 in. What is the measurement of this triangle’s largest angle? 29.9° 129.9° 136.2° 50.1°.

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Eliza 4 days 2022-01-14T11:54:37+00:00 1 Answer 0 views 0

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    2022-01-14T11:55:46+00:00

    Answer:

    x =  129.9 degrees to the nearest tenth.

    Step-by-step explanation:

    The largest angle will be opposite the longest side (20 in). So by the Cosine Rule:

    20^2 = 9^2 + 13^2 – 2*9*13 cos x      where x is the  largest angle.

    cos x =  (20^2-0.640 – 9^2 – 13^2) / (-2*9*13)

    cos x = -0.641025641

    x =  129.87 degrees.

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