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32 votes
Find the number that belongs in the green boxRound your answer to the nearest tenth.

Find the number that belongs in the green boxRound your answer to the nearest tenth-example-1
User Auggie N
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1 Answer

13 votes
13 votes

To solve the exercise you can use the cosine law, which applies to any triangle, its formula is


a^2=-2bc\cos (A)+b^2+c^2

So, in this case, you have


\begin{gathered} a^2=-2bc\cos (A)+b^2+c^2 \\ a^2=-2(8)(13)\cos (89)+(8)^2+(13)^2 \\ a^2=229 \\ \text{ Apply square root to both sides of the equation} \\ \sqrt[]{a^2}=\sqrt[]{229.37} \\ a=15.1 \end{gathered}

Therefore, the missing side measurement is 15.1 units.

Find the number that belongs in the green boxRound your answer to the nearest tenth-example-1
User Rep
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