Question 196201
sol:
the equation is of the form 
(x-h)^2+(y-k)^2=r^2
then the center=(h,k)
and radius=r
1)
(x-2)^2+(y-3)^2=16
comparing with 
(x-h)^2+(y-k)^2=r2
here h=2,k=3,r^2=16
center=(h,k)
center=(2,3)
r^2=16,r=sqrt(16)=4
radius=4
2)
(x+0)^2+(y+4)^2=8
here h=0,k=-4
center=(0,-4)
radius=sqrt(8)