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5 votes
Find the missing side or angle.

Round to the nearest tenth.
b=3
a=9
c=11
C= ?

1 Answer

4 votes

Answer:

C=125°

Explanation:

Hi there!

To find angle C, we can use the cosine law:


cosC=(a^2+b^2-c^2)/(2ab)

Plug in the given information


cosC=(9^2+3^2-11^2)/(2(9)(3))


cosC=(-31)/(54)


C=cos^-^1((-31)/(54))


C=cos^-^1((-31)/(54))\\C=125

Therefore, angle C is approximately 125 degrees.

I hope this helps!

User Tobsen
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