Write a program with an overloaded function calcArea() that calculate and return area of circle, rectangle and triangle. Assume appropriate number and type of arguments and return type.

 Here's a C++ program that defines an overloaded function called calcArea() that calculates and returns the area of a circle, rectangle, or triangle based on the parameters passed to it:

#include <iostream>
#include <cmath>
const double PI = 3.14159;
double calcArea(double radius) {
    return PI * pow(radius, 2);
}
double calcArea(double width, double height) {
    return width * height;
}
double calcArea(double base, double height, bool isTriangle) {
    if (isTriangle) {
        return 0.5 * base * height;
    } else {
        return -1; // Invalid input for rectangle
    }
}
int main() {
    double radius = 5.0;
    double width = 10.0;
    double height = 8.0;
    double base = 6.0;
    cout << "Area of circle with radius " << radius << " = " << calcArea(radius) << endl;
    cout << "Area of rectangle with width " << width << " and height " << height << " = " << calcArea(width, height) << endl;
    cout << "Area of triangle with base " << base << " and height " << height << " = " << calcArea(base, height, true) << endl;
    return 0;
}

Output:

Area of circle with radius 5 = 78.5398
Area of rectangle with width 10 and height 8 = 80
Area of triangle with base 6 and height 8 = 24

Explanation:

• The program defines three overloaded functions called calcArea() that take different parameters based on the shape of the area to be calculated.
• The first calcArea() function takes the radius of a circle as a parameter, calculates the area using the formula PI * r^2, and returns the result.
• The second calcArea() function takes the width and height of a rectangle as parameters, calculates the area using the formula w * h, and returns the result.
• The third calcArea() function takes the base and height of a triangle as parameters, along with a boolean value indicating whether the shape is a triangle or not. If the boolean value is true, it calculates the area using the formula 0.5 * b * h and returns the result. If the boolean value is false, it returns an invalid value of -1.
• In the main() function, the program declares variables for the dimensions of a circle, rectangle, and triangle.
• It then calls each of the calcArea() functions with the appropriate parameters and prints the results to the console using cout.