Write a c plus plus program to find the area of circle?

Answer 1

#include<stdio.h>

void main()

{

int r;

int pi=3.14;

float cir,area;

printf("/n enter the radius of the circle");

scanf("%d",&r);

cir=2*pi*r;

area=pi*r*r;

printf("the circumference of the circle is%d",cir);

printf('the area of the circle is %d",area);

}

Answer 2

/* To calculate the area and circumference of a circle, you need to know its radius. So likely the first thing to do would be to create two functions - getArea() and getCircumference() - which will each take the raduis as an argument and return their respective values:*/

#include <iostream>

#define pi 3.14159

int getArea(int radius) // Area = pi * r^2

{

return(pi * radius * radius);

}

int getCircumference(int radius) // Circumference = 2 * pi * r

{

return(2 * pi * radius);

}

// Now you can put these functions inside your main function with the proper values:

int main()

{

int radius = 5;

printf("A circle with radius %d has an area of %d and a circumference of %d\n", radius, getArea(radius), getCircumference(radius));

return 0;

}

Answer 3

#include<stdio.h>

#define pi 3.124

void main()

{

int r,c;

printf("enter the radius\n");

scanf("%d",&r);

c=pi*r*r;

printf("%d",c);

getch();

}

Answer 4

//This program will read in the radius of any circle and determine and print it area

#include <iostream>

#include <math.h>

using namespace std;

int main ()

{

int r;

double area;

// The following will allow you to keep the answer to 2places after the decimal

cout.self(ios::fixed,ios::floatfield);

cout.precision(2);

cout <<"Enter the radius of the circle ";

cin >>r;

// The area of an circle is A= pie * r squared

area= pow(r,2) * 3.14;

cout <<" The area of a circle with a radius of "<< r <<" is "<< area;

return 0;

}

Answer 5

You don't say how accurate you want it. Here's a version using doubles:

const double PI = 4*atan(1.0);

const double AreaOfCircle( const double radius ) {

return( PI * radius * radius ); }

Answer 6

#include<studio.h>

main()

{

int r,area;

printf("enter value of radius");

Scanf("%d",&r);

area=(22/7)*r*r;

printf("area=%d",area);

}

Answer 7

double AreaOfCircle (double Radius) return Radius * Radius * 3.14159265358979;