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Ok very confused on this problem, can you help me out?

Ok very confused on this problem, can you help me out?-example-1

1 Answer

2 votes

Given the triangle ABC, you need to remember that, by definition:

- The longest side of a triangle is opposite the largest angle of the triangle.

- The shortest side of a triangle is opposite the smallest angle of the triangle.

In this case, you can identify that:

• The largest angle of the triangle is:


m\angle B=87\text{\degree}

And the side opposite it is the longest side:


AC=29

• The smallest angle is:


m\angle C=43\text{\degree}

Since the side opposite to this angle is:


AB=4x

You know that this must be the shortest side of the triangle. Therefore, this must be less than 29 and also less than 22. Notice that:

1. If:


x=10

Then:


AB=4(10)=40

2. If:


x=6

Then:


AB=4(6)=24

3. If:


x=5

Then:


AB=4(5)=20

4. If:


x=7

Then:


AB=4(7)=28

Notice that the only length less than 29 and less than 22, is obtained by substituting this value of "x" into the expression for the side AB:


x=5

Hence, the answer is: Third option.

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