Write a program to calculate the area of circle, triangle, rectangle and square using function overloading.

Sure, here is a Python program that uses function overloading to calculate the area of a circle, triangle, rectangle, and square.

In Python, we don't have built-in function overloading. We can achieve similar functionality using optional parameters, or by checking the type of the arguments passed.

import math

def calculate_area(shape, a=None, b=None):
    if shape == 'circle':
        if a is None:
            print("You need to provide the radius for a circle")
            return None
        else:
            return math.pi * a * a
    elif shape == 'triangle':
        if a is None or b is None:
            print("You need to provide the base and height for a triangle")
            return None
        else:
            return 0.5 * a * b
    elif shape == 'rectangle':
        if a is None or b is None:
            print("You need to provide the length and width for a rectangle")
            return None
        else:
            return a * b
    elif shape == 'square':
        if a is None:
            print("You need to provide the side length for a square")
            return None
        else:
            return a * a
    else:
        print("Unknown shape")
        return None

# Test the function
print(calculate_area('circle', a=5))
print(calculate_area('triangle', a=5, b=10))
print(calculate_area('rectangle', a=5, b=10))
print(calculate_area('square', a=5))

In this program, the calculate_area function takes the shape name and the necessary parameters for that shape. It then calculates the area based on the shape. If the necessary parameters are not provided, it prints an error message and returns None.