Answer:
r = √14
Step-by-step explanation:
Is this what you meant? If so heres' the answer
Equation of circle
Center the origin
r = √14
Answer: True
Explanation: hope this help
The answer would look something like this:

There could also have a simplified version.
I hope this helps.
Answer:
5 x 2 x 3.14 = 31.4
Formula of circumference:
radius(half of your diameter or given radius) x pi(3.14 or 22/7 depending on what they tell you to use for pi) x 2(just always there when finding circumference)