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 
Answer:
Wave length = speed / frequency
Wave length = 3x10^8 / 4.11x10^4
Wave length = 7.299x10^3nm
Step-by-step explanation:
As IQ scores for extensive populaces are focused at 100, the mean = 100.
There ought to be around half scores above or underneath the mean score since mean and middle is about a similar when the populace is substantial.
P(x > 100) = P( z> (100 - 100)/sd ) = P(z > 0)= 0.5
The number of the student who has scored over 100 = 0.5 x 78 = 39 Therefore the answer is 39 students.
you have to add 90 +90 3 times then theres your answer :)
The probability the spinner lands on a prime number is 4/10 or 40%