how do i round to 3 decimal places

Question

My code shows 3 decimal places but in the 3rd decimal place its always a 0. What can I do to fix this to where it gives me the third number.

print ('Radius     Area     Circumference')

for Radius in range(1 , 11):

    Area = (Radius)**2*3.14
    Circumference =  (Radius)*2*(3.14)
    a = Radius
    b = Area
    c = Circumference



    print ('{:2d}    {:10.3f}   {:10.3f}'.format(a, (b), (c)))

here is an example of how its reading out.

Radius     Area     Circumference
 1         3.140        6.280
 2        12.560       12.560
 3        28.260       18.840
 4        50.240       25.120

Answer 1

import math

print ('Radius     Area     Circumference')

for radius in range(1 , 11):
    area = radius**2*math.pi
    circumference =  radius*2*math.pi
    print('{:2d}    {:10.3f}   {:10.3f}'.format(radius, area, circumference))