Answer:
i sry i need points
Step-by-step explanation:
Answer:
The radius is: 
Step-by-step explanation:
The equation of a circle in center-radius form is:

Where the center is at the point (h, k) and the radius is "r".
So, given the equation of the circle:

You can identify that:

Then, solving for "r", you get that the radius of this circle is:

Answer:
46.2
Step-by-step explanation:
If you divide 231 by 5 then you get that answer.
81, if you mean 9 Squared.