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Need help QUICK! Given triangle ABC, which equation could be used to find the measure of angle B?

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Need help QUICK! Given triangle ABC, which equation could be used to find the measure-example-1
User AJ Acevedo
by
4.9k points

2 Answers

3 votes

Answer:

2 Square 5/ 5

Explanation:

I got it right on the test

User Andrew Kashpur
by
5.2k points
7 votes

Answer:

second option

Explanation:

We are going to use the acronym:

"Soh Cah Toa".

Why? It tells us the right-triangle definitions of sine, cosine, and tangent.

sine is opposite over hypotenuse.

cosine is adjacent over hypotenuse.

tangent is opposite over adjacent.

So looking at our triangle with respect to B tells us that 3 is the opposite measurement and 6 is the adjacent. No matter what angle we are looking for in this triangle, the hypotenuse is constantly going to by
3√(5).

So let's look at cos(B).


\cos(B)=(6)/(3√(5))

We need to rationalize the denominator by multiplying top and bottom by sqrt(5):


\cos(B)=(6√(5))/(3(5))=(2√(5))/(5)

So now looking at sin(B).


\sin(B)=(3)/(3√(5))

We have to rationalize again by multiplying top and bottom by sqrt(5):


\sin(B)=(3√(5))/(3(5))=(√(5))/(5).

So looking at our triangle with respect to A tells us that 3 is the adjacent measurement and 6 is the opposite. No matter what angle we are looking for in this triangle, the hypotenuse is constantly going to by
3√(5).

We don't have to use any trigonometric ratios with A.

User Jodian
by
5.6k points
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