A necessary and sufficient condition for the curve of equation (x-a) * 2 + (y-b) * 2 = R * 2 to pass through the origin

A necessary and sufficient condition for the curve of equation (x-a) * 2 + (y-b) * 2 = R * 2 to pass through the origin

Over origin
x=0,y=0
So the necessary and sufficient condition is a & sup2; + B & sup2; = R & sup2;