Solution Exercise 44: class circle en python

Exercise 44. Circle class

1 - Define a Circle class allowing to create a circleC (O, r) with center O(a, b) and radius r using the constructor:

    def __init__(self,a,b,r):         
        self.a = a         
        self.b = b         
        self.r = r

2 - Define a Area() method of the class which calculates the area of ​​the circle.
3 - Define a Perimeter() method of the class which allows you to calculate the perimeter of the circle.
4 - Define a testBelongs() method of the class which allows to test whether a point A(x, y) belongs to the circle C(O, r) or not.

Solution

from math import pi
class Circle:
    def __init__(self, a, b, r):
        self.a = a
        self.b = b
        self.r = r

    def perimeter (self):
        return  2 * pi * self.r


    def area (self):
        return  pi * self.r**2
    

    # form of the cercle equation 
    def formEquation (self, x, y):
        return (x-self.a)**2 + (y-self.b)**2 - self.r**2
    
    # method to test if given point blong to the circle or not 
    def test_belong (self, x, y):
        if (self.formEquation (x, y) == 0):
            print ("the point: (", x, y, ") belongs to the circle C")
        else:
            print ("the point: (", x, y, ") does not belong to the circle C")


# Creating of an instance object
C = Circle (1,2,1)

print ("the perimeter of the circle C is:", C.perimeter() )
print ("the area of circle C is:", C.area())
# we test if the point(1,1) belong to the circle or not
C.test_belong(1,1) 
# The output is:
#the perimeter of the circle C is: 6.283185307179586
#the area of circle C is: 3.141592653589793
#the point: ( 1 1 ) belongs to the circle C