The formula for arc length is s=r*angle theta where s is the arc length, r is the radius, and angle theta is central angle formed by the arc in radians.
In this case, the angle would be s/r or 4.2/4 which is 1.05 radians. We have to convert this into degrees and so you would multiply 1.05 by (180/pi) which results in approximately 60 degrees. Remember, if you want to convert radians into degrees, the conversion factor is 180/pi and for degrees into radians, it is pi/180.
3 -1i + 21i -7i2 now you have to fix the last factore because you have to change the imaginery i this would give you the answer of 3 - 1i + 21i +7 now add common factor which would give you the final answer of 3 +20i +7
Answer: Number of ways 
Step-by-step explanation:
When there is no replacement , we use combination to find the number of ways to choose things.
Number of ways to choose r things out of ( with out replacement) = 
The number of ways to choose 8 things = ![^8C_8=\dfrac{8!}{8!(8-8)!}=\dfrac{1}{0!}=1 [\because 0!=1]](https://tex.z-dn.net/?f=%5E8C_8%3D%5Cdfrac%7B8%21%7D%7B8%21%288-8%29%21%7D%3D%5Cdfrac%7B1%7D%7B0%21%7D%3D1%20%20%5B%5Cbecause%200%21%3D1%5D)
Hence, Number of ways 
Answer:
11.9 mm
Step-by-step explanation:
We can find d by applying the cosine rules.
d² = 21² + 27² - 2(21)(27) cos (25)
d² = 441 + 729 - 1027.75
d² = 142.25
d = √142.25
d = 11.9 mm (nearest tenth)
C(h,k) radius(r)
C(2,-3) r=4
(x-h)^2 + (y-k)^2 = r^2
(x-2)^2 + (y--3)^2 = 4^2
(x-2)^2 + (y+3)^2 = 16
therefore, the answer is D