/************************************************* Remy's Circle Equation Calculation Program **************************************************/#include <stdio.h>#include <stdlib.h>#include <conio.h>#include <ctype.h>#define PI 3.14float a, c, r, x;char quit;float area(void);float circ(void);int main(){ do { printf("Press A for area, C for circumference.\n"); c=toupper(getch()); if (c=='A') { printf("You chose area.\n"); printf("Enter the radius:"); a=area(); printf("The area of the circle is %f.\n",a); printf("Do you want to quit? Y/\N?\n"); quit=toupper(getch()); } else if (c=='C') { printf("You chose circumference.\n"); printf("Enter the radius:"); c=circ(); printf("The circumference of the circle is %f.\n",c); printf("Do you want to quit? Y/\N?\n"); quit=toupper(getch()); } else { printf("Invalid choice.\n"); printf("Do you want to quit? Y/\N?\n"); quit=toupper(getch()); } } while (quit == 'N'); return 0;}float area(void){ scanf("%f", &r); x=PI*(r*r); return(x);} float circ(void){ scanf("%f", &r); x=2*PI*r; return(x);}