we know that
The measurement of <u>the external angle</u> is the semi-difference of the arcs it includes.
In this problem
![21\°=\frac{1}{2}[arc\ RU-arc\ SU]](https://tex.z-dn.net/?f=21%5C%C2%B0%3D%5Cfrac%7B1%7D%7B2%7D%5Barc%5C%20RU-arc%5C%20SU%5D)
Solve for the measure of arc SU
![42\°=[arc\ RU-arc\ SU]](https://tex.z-dn.net/?f=42%5C%C2%B0%3D%5Barc%5C%20RU-arc%5C%20SU%5D)


therefore
the answer is
The measure of the arc SU is 
The answer is: 
The explanation is shown below:
1. Cynthia rounds the number, which is identified as
, to one decimal place and the result is 6.3.
2. Based on this, we know that
could have been between 6.25 and 6.35. Therefore, the error interval for
is given by:

Where
indicates that the value 6.25 is included and
indicates that the value 6.35 is not included (Because if
had been exactly 6.35, Cynthia would round up to 6.4).
Answer:
A. 1 in. = 22.5 mi
Step-by-step explanation:
Since 22.5 x 10 = 225, we can conclude that this will fit the scale needed. B. is incorrect because it is simply illogical in context with a scale and the question. C. is incorrect since 10 x 0.04 is 0.4, which does not equal 10. D. is incorrect since we need the scale to add up to equal 225 mi, not 22.5.
Hope this helps!