As the question say this problem is a practice of the law of cosines!
The law of cosine: c^2=a^2+b^2-2ab*cos*c for any side a, b and c
The law can also be written as c=sqrt(a^2+b^2-2abcosc)
Now use this formula!(note cos 100 degrees is about 0.8623)
c=sqrt(15^2+16^2-2*15*16*cos100)
solving this we can MN is about 23.75
Round this to the nearest tenths now!
We get 23.8!
Thus the answer is D
Explanation:
If your actual answer is very far from your estimate, you probably made a mistake somewhere.
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<em>Additional comment</em>
50 years ago, when a slide rule was the only available calculation tool, making an estimate of the result was a required part of doing the calculation. Not only were the first one or two significant digits needed, but also the power of 10 that multiplied them. Use of a slide rule required the order of magnitude be computed separately (by hand) from the significant digits of the result.
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You may also find it useful to estimate the error in your estimate. That is, you may want to know the approximate answer to 2 (or more) significant digits in order to gain confidence that your calculation is correct.
<span>
Slope = 3
x-intercept = 28/3 = 9.33333<span>
y-intercept = 28/-1 = -28.00000
Hope this helped</span></span>
