Final answer:
A class named 'Circle' with 'center' (a Point object) and 'radius' (a number) can be defined in Python. To instantiate a Circle object with a center at (150, 100) and a radius of 75, create a Point object for the center and then use it to create the Circle object.
Step-by-step explanation:
To define a class named Circle with the attributes center and radius, where center is a Point object and radius is a number, you would use the following Python code:
class Point:
def __init__(self, x, y):
self.x = x
self.y = y
class Circle:
def __init__(self, center, radius):
self.center = center
self.radius = radius
Then, to instantiate a Circle object that represents a circle with its center at (150, 100) and a radius of 75, you would write:
center_point = Point(150, 100)
circle = Circle(center_point, 75)
Note that the Point class must be defined to create a center object that can be passed to the Circle class.