Question

Help me please with circles

Answer 1

The equation of a circle is (x-k)^2+(y-h)^2=R^2, where (k,h) is the center of the circle, R - its raduis.
In our case
x^2+y^2=10^2, therefore k=0, h=0, R=10.

Answer: the center is (0, 0); the radius is 10.