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Help with #2 please and thanksFind the measure of angle C

Help with #2 please and thanksFind the measure of angle C-example-1
User Highrule
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1 Answer

6 votes

Answer:


C\text{ = 83.34}\degree

Step-by-step explanation:

Here, using the cosine law, we want to calculate the measure of angle C

According to the law:


c^2\text{ = a}^2+b^2-2abCosC

where:

a = 8

b = 7

c = 10

we want to find C

Substituting the values, we have it that:


\begin{gathered} 10^2\text{ = 8}^2+7^2-2(8)(7)cosC \\ 100-64-49\text{ = -112 cos C} \\ 13\text{ = 112 cos C} \\ cos\text{ C = }(13)/(112) \\ \\ cos\text{ C = 0.1160} \\ C\text{ = }\cos^(-1)\text{ 0.1160} \\ C\text{ = 83.34}\degree \end{gathered}

User Isura Amarasinghe
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4.4k points