standard equation for a circle is: (x -h)² + (y - k)² = r²
(h,k) is the center which is given to be: (0,0) so you just need the radius.
The radius is the distance from the center to the point (-4,5) on the edge.
Use the distance formula
d = √[(-4 - 0)² + (5 -0)²]
d = √[16 + 25]
d = √[41]
radius is √[41]
so the equation for the circle is: x² + y² = 41
