C++ Program to Calculate the Area and Perimeter of Different Shapes

This page contains a C++ program that calculates the area and perimeter of a circle, rectangle, and triangle. The program uses basic geometric formulas to perform these calculations.

Program Explanation

The C++ program to calculate the area and perimeter of different shapes follows these steps:

1. Include necessary headers: Include the <iostream> and <cmath> headers for input/output functions and mathematical functions.
2. Define functions: Create separate functions for calculating the area and perimeter of each shape.
3. Main Function: The main function is the entry point of the program, which calls these functions and displays the results.

C++ Program Code

/*
 * C++ program to calculate the area and perimeter of different shapes.
 */
#include <iostream>
#include <cmath>

using namespace std;

// Function prototypes
void calculateCircle();
void calculateRectangle();
void calculateTriangle();

int main() {
    // Calculate and display area and perimeter for different shapes
    calculateCircle();
    calculateRectangle();
    calculateTriangle();

    return 0;
}

/**
 * Function to calculate and display the area and circumference of a circle.
 */
void calculateCircle() {
    double radius;
    cout << "Enter the radius of the circle: ";
    cin << radius;
    
    double area = M_PI * radius * radius;
    double circumference = 2 * M_PI * radius;
    
    cout << "Area of the circle: " << area << endl;
    cout << "Circumference of the circle: " << circumference << endl;
}

/**
 * Function to calculate and display the area and perimeter of a rectangle.
 */
void calculateRectangle() {
    double length, width;
    cout << "Enter the length and width of the rectangle: ";
    cin << length << width;
    
    double area = length * width;
    double perimeter = 2 * (length + width);
    
    cout << "Area of the rectangle: " << area << endl;
    cout << "Perimeter of the rectangle: " << perimeter << endl;
}

/**
 * Function to calculate and display the area and perimeter of a triangle.
 */
void calculateTriangle() {
    double a, b, c;
    cout << "Enter the three sides of the triangle: ";
    cin << a << b << c;
    
    double s = (a + b + c) / 2;
    double area = sqrt(s * (s - a) * (s - b) * (s - c));
    double perimeter = a + b + c;
    
    cout << "Area of the triangle: " << area << endl;
    cout << "Perimeter of the triangle: " << perimeter << endl;
}

Program Details

The program contains the following:

• calculateCircle Function: This function prompts the user for the radius of a circle, calculates the area using the formula πr2, and the circumference using the formula 2πr.
• calculateRectangle Function: This function prompts the user for the length and width of a rectangle, calculates the area using the formula length × width, and the perimeter using the formula 2(length + width).
• calculateTriangle Function: This function prompts the user for the three sides of a triangle, calculates the area using Heron’s formula sqrt(s(s-a)(s-b)(s-c)) where s = (a + b + c) / 2, and the perimeter as the sum of the sides.
• main Function: The entry point of the program where the shape-specific functions are called to perform the calculations and display the results.

Running the Program

To run the program:

1. Save the code in a file named shape_calculations.cpp.
2. Compile the program using the command: g++ shape_calculations.cpp -o shape_calculations.
3. Run the compiled program using the command: ./shape_calculations.

Explanation of the C++ Program:

1. Header Inclusions: The program includes <iostream> for input/output functions and <cmath> for mathematical functions.
2. Function Prototypes: The program declares prototypes for three functions: calculateCircle, calculateRectangle, and calculateTriangle.
3. Main Function:
   • Calls each of the shape-specific functions to perform the calculations and display the results.
4. calculateCircle Function:
   • Prompts the user to enter the radius of the circle.
   • Calculates the area using the formula πr2\pi r^2πr2 and the circumference using the formula $2\pi r$.
   • Displays the calculated area and circumference.
5. calculateRectangle Function:
   • Prompts the user to enter the length and width of the rectangle.
   • Calculates the area using the formula $\text{length}\times \text{width}$ and the perimeter using the formula $2(\text{length}+\text{width})$.
   • Displays the calculated area and perimeter.
6. calculateTriangle Function:
   • Prompts the user to enter the three sides of the triangle.
   • Calculates the semi-perimeter $s$ using the formula s=a+b+c2s = \frac{a + b + c}{2}s=2a+b+c​.
   • Calculates the area using Heron’s formula s(s−a)(s−b)(s−c)\sqrt{s(s-a)(s-b)(s-c)}s(s−a)(s−b)(s−c)​.
   • Calculates the perimeter as the sum of the sides $a+b+c$.
   • Displays the calculated area and perimeter.