Write a program that displays the following menu

 
 #include <stdio.h> 
 #include <math.h> 
  
 #define PI 3.14159 
  
 int main(void) { 
  
     int choice; 
  
     double r, length, width, base, height; 
  
     printf("1. Calculate the Area of a Circle\n2. Calculate the Area of a Rectangle\n3. Calculate the Area of a Triangle\n4. Quit\n"); 
  
     scanf("%d", &choice); 
  
     switch (choice) { 
  
         case 1: 
  
             printf("Please enter the radius of the circle: \n"); 
  
             scanf("%lf", &r); 
  
             while (r < 0) { 
  
                 printf("Please re-enter the radius of the circle: \n"); 
  
                 scanf("%lf", &r); 
  
             } 
  
             printf("Area of the circle is %f\n", PI * pow(r, 2)); 
  
             break; 
  
         case 2: 
  
             printf("Please enter the length and width of the rectangle\n"); 
  
             scanf("%lf %lf", &length, &width); 
  
             while (length < 0) { 
  
                 printf("Please re-enter the length of the rectangle: \n"); 
  
                 scanf("%lf", &length); 
  
             } 
  
             while (width < 0) { 
  
                 printf("Please re-enter the width of the rectangle: \n"); 
  
                 scanf("%lf", &width); 
  
             } 
  
             printf("Area of the rectangle is %f\n", length * width); 
  
             break; 
  
         case 3: 
  
             printf("Please enter the base and height of the triangle\n"); 
  
             scanf("%lf %lf", &base, &height); 
  
             while (base < 0) { 
  
                 printf("Please re-enter the base of the triangle: \n"); 
  
                 scanf("%lf", &base); 
  
             } 
  
             while (height < 0) { 
  
                 printf("Please re-enter the height of the triangle: \n"); 
  
                 scanf("%lf", &height); 
  
             } 
  
             printf("Area of the triangle is %f\n", base * height * .5); 
  
             break; 
  
         case 4: 
  
             break; 
  
         default: 
  
             printf("INVALID INPUT!\n"); 
  
             main(); 
  
     } 
  
     return (0); 
  
 }