C Program to calculate area of a circle

Algorithm

Input: Read radius from the user
output: Display the area of the circle

1. Start
2. Input radius
3. Area = 3.14 * r * r
4. Print Area
5. Stop

C Program

#include <stdio.h>

#include <math.h>

int main( )

{

float r, area;

printf("Enter the radius of the circle: ");

scanf("%f", &r);

area = M_PI * pow(r, 2); //M_PI is the value of PI and pow(r,2) is r square

printf("The area of the circle with radius %f is %f", r, area);

return 0;

}