Answer:
3
Step-by-step explanation:
I think its three i dont do alot of this but yea
You just have to answer to all of the questions and bullet points. Think about them, and do some sketches. In the end that will help you to end the assignment.
Hope it helped.
Answer:

Step-by-step explanation
The standard equation of a circle centered at origin is 
r = radius of the circle
The circle is passing through the point (0,5)
∴ radius 



∴ The equation of the circle is

3/12x5 is the answer of your question.