Notice the picture below

you have the center, the h,k, all you really need is the radius "r"
Answer:
Step-by-step explanation:
list of prime numbers from 1-21
2,3,5,7,11,13,17,19
he has 21 students
the only numbers he can divide by is 3 and 7
21/3=7
21/7=3
Answer:
4 is always correct
Step-by-step explanation: