switchCase

#include <iostream>
using namespace std;

int main()
{
    struct circle
    {
        float radius;
        float diameter;
    };

    struct square
    {
        float side;
    };

    struct rectangle
    {
        float length;
        float width;
    };

    struct triangle
    {
        float base;
        float height;
    };

    char choice;
    struct circle circle;
    struct square square;
    struct rectangle rectangle;
    struct triangle triangle;

    cin >> choice;

    switch(choice)
    {
        case 'C':
            cout << "Enter radius: ";
            cin >> circle.radius;
        cout << 3.14 * (circle.radius * circle.radius) << endl;
            break;
        case 'S':
            cout << "Enter side: ";
            cin >> square.side;
            cout << square.side * square.side;
            break;
        case 'R':
            cout << "Enter length: ";
            cin >> rectangle.length;
            cout << "Enter width: ";
            cin >> rectangle.width;
            cout << rectangle.length * rectangle.width;
            break;
        case 'T':
            cout << "Enter base: ";
            cin >> triangle.base;
            cout << "Enter height: ";
            cin >> triangle.height;
            cout << 0.5 * (triangle.base * triangle.height);
            break;


    default:
        cout << "Invalid Entry" << endl;
        break;
    }
}