Check if a circle is contained in another circle

Question

I'm trying to check if a circle is contained within another circle. I'm not sure if the math behind it is the problem or if its my if statement because I keep getting True for anything I pass.

#Get_center returns (x,y)
#Get_radius returns radius length
def contains(self,circle):
    distance = round(math.sqrt((circle.get_center()[0]-self.get_center()[0])**2 + (circle.get_center()[1] - self.get_center()[1])**2))
    distance_2 = distance + circle.get_radius()
    if distance_2 > distance:
        return True        #Circle 2 is contained within circle 1

Answer 1

I don't know about python but the math is simple. See the below picture

To check if circle 2 inside circle 1,

compute d 
    d = sqrt( (x2-x1)^2 + (y2-y1)^2 );
get c2 and c1
if c1 > ( d + c2 ) 
   circle 2 inside circle 1
else
   circle 2 not inside circle 1

Answer 2

CODE ACCORDING TO THE IMAGE IN THE ACCEPTED ANSWER (without getters, as it's more readable):

import math
def contains(self, circle):
  d = math.sqrt(
        (circle.center[0] - self.center[0]) ** 2 +
        (circle.center[1] - self.center[1]) ** 2)
  return self.radius  > (d + circle.radius)

I used it, and it works. In the following plot, you can see how the circles completely contained in the red big one are painted in green, and the others in black: