Question

Given a=8, b=7 and c =6, use the law of cosines to solve the triangle for the value of C. Round answer two decimal.

a. 80.44
b. 46.57
c. 57.91
d. 75.52

Answer 1

B) 46.67°

Explanation:

Step 1 : Write the cosine formula to find the angle C

c² = a² + b² - 2ab cos C

Step 2 : Substitute the values in the formula

6² = 7² + 8² - 2(8)(7) cos C

cos C = 0.6875

C = cos^-1 (0.6875)

C = 46.567 °

Step 3 : Round off to 2 decimal places

Angle C = 46.57°

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