Find the distance between the nearest point and the center of the circle Distance between 2 points , ( x1 , y1 ) & ( x2 , y2 ) in 2D Euclidean space is ( ( x1 - x2 ) * * 2 + ( y1 - y2 ) * * 2 ) * * 0.5
let Dx = Xn - Xc ; let Dy = Yn - Yc ; return ( Dx * Dx + Dy * Dy ) <= R * R ; }