def area_of_circle(radius):
    """
    Calculate area of circle based on radius.
    """
    import math

    return math.pi * (radius ** 2)


def area_of_rectangle(length, width):
    """
    Calculate area of rectangle based on length and width.
    """
    return length * width


def area_of_square(side_length):
    """
    Calculate area of square based on side length.
    """
    return side_length ** 2
