Is there a picture that goes with the question ?
Answer:
Third option.
Step-by-step explanation:
You need to remember that the formula used to calculate the arc lenght is:

Where "r" is the radius and "C" is the central angle in radians.
You need to solve for "C":
You know the radius and the arc lenght, therefore, you can substitute values to calculate the central angle in radians. Therefore, this is:

Answer:
Solve the equation for s by finding a , b , and c of the quadratic then applying the quadratic formula.
s
=
−
2
Double roots
I would would say 7.
Mom + Dad + daughter + daughter + daughter + daughter + plus one brother = 7
Since they are all sisters and it says each one has one brother I think that would mean 7. That's just my comprehension of the question, though I may 100% wrong.
All of the equations contain -4 in their range.
A) -4 = sqrt(x) - 5
1 = sqrt(x)
x = 1; valid
B) -4 = sqrt(x) + 5
-9 = sqrt(x)
x = 81; valid
C) -4 = sqrt(x + 5)
16 = x + 5
x = 11; valid
D) -4 = sqrt(x - 5)
16 = x - 5
x = 21
I believe the equations contain square instead of square root, in which case the answer would be A because no other could have a negative range.