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45 votes
HELP PLEASE! THIS IS DUE SOON! HELP ME! QUESTION BELOW!

HELP PLEASE! THIS IS DUE SOON! HELP ME! QUESTION BELOW!-example-1
User Jmatraszek
by
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1 Answer

20 votes
20 votes

Answer:

A) x = 113°

Step-by-step explanation:

Given three sides: 6.4 cm, 5.8 cm, 10.2 cm

Use the cosine rule:

c² = a² + b² - 2ab cos(C)

Insert/put variables:


\rightarrow \sf 10.2^2 = 5.8^2 + 6.4^2 - 2(5.8)(6.4) cos(x)


\rightarrow \sf -74.24 cos(x) = 10.2^2 - 5.8^2 - 6.4^2


\sf \rightarrow -74.24 cos(x) = 29.44


\rightarrow \sf cos(x) = (29.44)/(-74.24)


\rightarrow \sf x = cos^(-1)(-(23)/(58)) = 113.36° ≈ 113° (rounded to nearest degree)

User Itsmcgh
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3.4k points