#include <stdio.h> 

int main() { 
    int choice; 
    double radius, length, width, side, base, height, area;
    
    printf("--- Area Calculator ---\n");
    printf("1. Circle\n2. Rectangle\n3. Square\n4. Triangle\n"); 
    printf("Enter your choice (1-4): "); 
    scanf("%d", &choice);

    switch (choice) {
        case 1:
            printf("Enter radius: ");
            scanf("%lf", &radius);       
            area = 3.14159 * radius * radius;
            printf("Area of Circle = %.2f\n", area);
            break;
        case 2: 
            printf("Enter length and width: "); 
            scanf("%lf %lf", &length, &width);  
            area = length * width; 
            printf("Area of Rectangle = %.2f\n", area); 
            break;

        case 3: 
            printf("Enter side length: "); 
            scanf("%lf", &side);           
            area = side * side;
            printf("Area of Square = %.2f\n", area);
            break;

        case 4:
            printf("Enter base and height: "); 
            scanf("%lf %lf", &base, &height);   
            area =  0.5 * base * height;
            printf("Area of Triangle = %.2f\n", area);
            break;
        default: 
            printf("Invalid choice!\n");
        }
    return 0;
}