C Program to find area and circumference of circle- GET EDUCATE

Contents

Introduction to Problem Solving

⯈Introduction

⯈Algorithm and its Characteristics

⯈Flowcharts and its Notations

⯈Elementary Problems

Basics of C Programming

⯈Basic C Programs

C Program to find area and circumference of circle

We start the program by reading the necessary inputs and then conclude the program with calculating the outputs.

Input: radius (double)

Output: area (double) and circumference (double)

Reading the inputs,

Let ‘r’ be the radius.

scanf("%lf", &r);

No variable should be used unless it is declared, and since we have used scanf function we need stdio.h

#include<stdio.h>
int main()
{
    double r;
    scanf("%lf",&r);
    ...
}

It is good to give a user interface before we read the input, therefore, we write,

#include<stdio.h>
int main()
{
   double r;
   printf("Enter radius r:");
   scanf("%lf", &r);
   ......
}

Calculating the output,

area = 3.142 * r * r;

cir = 2 * 3.142 * r;

No variables should be used unless they are declared. We go up the ladder and declare area and cir.

#include<stdio.h>
int main()
{
    double r;
    double area, cir;
    printf("Enter radius:");
    scanf("%lf",&r);
    area = 3.142 * r * r;
    cir = 2 * 3.142 * r;
    .......
}

After we calculate all the outputs, its the time to display them.

Therefore, the final program becomes.

#include<stdio.h>
int main()
{
    double r;
    double area, cir;
    printf("Enter radius:");
    scanf("%lf",&r);
    area = 3.142 * r * r;
    cir = 2 * 3.142 * r;
    printf("area = %lf\n",area);
    printf("circumference = %lf\n",cir);
    return 0;
}