In triangle ABC, a = 3, b = 5, and c = 7. Find the approximate value of angle A.

Question

Mathematics

Jameson

26 August, 15:22

In triangle ABC, a = 3, b = 5, and c = 7. Find the approximate value of angle A.

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Answers (1)

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Caden Oneill · Answer 1

21.8° (22° to the nearest degree)

Step-by-step explanation:

Using cosine law:

a² = b² + c² - 2bc (cosA)

3² = 5² + 7² - 2 (5) (7) cosA

cosA = 13/14

A = 21.7867893

Approximately angle: 22°