Question

HELP, i really need help with these for questions, I’ll give Brainliest to whoever answers first, random answers will be reports.

Answer 1

The angles and lengths of each of the given triangles are;

5) m∠B = 57.52°

6) B = 70.81°

7) AB = 55.43 Km

8) AC = 39.06 ft

How to use cosine rule?

The cosine rule is expressed as;

c = √[a² + b² - 2ab(cos C)]

5) Using cosine rule;

BC = √[21² + 13² - 2(21*13)(cos 91)]

BC = 24.89

Using sine rule, we can find angle B as;

21/sin m∠B = 24.89/sin 91

sin m∠B = (21 * sin 91)/24.89

sin m∠B = 0.8436

m∠B = sin⁻¹0.8436

m∠B = 57.52°

6) Using cosine rule;

14² = 11² + 13² - 2(11*13)(cos B)]

196 = 121 + 169 - 286(cos B)

cos B = (121 + 169 - 196)/286

cos B = 0.3287

B = cos⁻¹0.3287

B = 70.81°

7) Using cosine rule;

AB = √[24² + 36² - 2(24*36)(cos 134)]

AB = 55.43 Km

8) Using cosine rule;

AC = √[21² + 26² - 2(21*26)(cos 112)]

AC = 39.06 ft

Read more about cosine rule at; brainly.com/question/4372174

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