menu.cpp

#include<stdio.h> //scanf printf
#include<stdlib.h>  //exit(0)
float tempF2C(float Tf);//function declaration
void areaOfCircle();
float m2inches(float m);
float miles2km(float miles);
float km2miles(float km);
int main()
{
    unsigned int ans = 0;
    do {
        system("cls");
        printf("1-Area of Circle\n");
        printf("2-FtoC\n");
        printf("3-m2inches\n");
        printf("4-miles2km\n");
        printf("5-km2miles\n");
        printf("6-Exit\n");
        printf("please choose 1,2,3,4,5,6: ");
        scanf_s("%d", &ans);
        if (ans == 1) areaOfCircle();
        else if (ans == 2) printf("Tc = %f\n", tempF2C(100));
        else if (ans == 3) printf("inches = %f\n", m2inches(4));
        else if (ans == 4) printf("km = %f\n", miles2km(10));
        else if (ans == 5) printf("miles = %f\n", km2miles(10));
        else if (ans == 6) {
            printf("Bye!\n\n");
            exit(0);
        }
        system("pause");
    } while (ans != 6);
    return 0;
}

void areaOfCircle()  //camel case
{
    float A = 0.0F;
    float r = 0.0F;
    printf("please enter radius: ");
    scanf_s("%f", &r);
    A = 3.14 * r * r;
    printf("Area of Circle = %f sq meter\n", A);
}


float tempF2C(float Tf) //function definition
{
    float Tc = 0.0F;
    Tc = (5.0F / 9.0F) * (Tf - 32.0F);
    return Tc;
}

float m2inches(float m)
{
    return 39.3701 * m;
}

float miles2km(float miles)
{
    return 1.60934 * miles;
}
float km2miles(float km)
{
    return 0.621371 * km;
}