import math

def dist2(x1,y1,x2,y2):
    return math.sqrt((x1 - x2)**2 + (y1 -y2)**2)

def dist3(x1,y1,x2,y2):
    return (abs(x1 - x2)**3 + abs(y1 -y2)**3)**(1/3)

def dins_circumferencia(x1,y1,x2,y2,r,eps):
    dist = dist2(x1,y1,x2,y2)
    return abs(dist-r)<eps