C Program to Find Area of a Circle

Area of a Circle formula

Area of a Circle = π * (radius*radius)

C Program to find the area of circle

This C program gets radius as user inputs and computes the area of a circle.

#include<stdio.h>                                                                
                                                                                
void main()
{
    int radius;
    float area=0;
    printf("\nFinds area of circle\n-------------------");
    printf("\nEnter radius: ");
    scanf("%d", &radius);

    area = 3.14*(radius*radius);

    printf("Circle Area: %.2f", area);
}
                                                                    
                                                                                  

$ cc area-of-circle.c 
$ ./a.out 

Finds area of circle
-------------------
Enter radius: 8
Circle Area: 200.96

Area of Semi-circle formula

Area of Semi-circle = ( π * radius*radius)/2

C Program to find the area of circle

This C program gets radius as user inputs and computes the area of semi-circle.

#include<stdio.h>                                                                
                                                                                
void main()
{
    int radius;
    float area=0;
    printf("\nFinds area of semi-circle\n-------------------");
    printf("\nEnter radius: ");
    scanf("%d", &radius);

    area = (3.14*radius*radius)/2;

    printf("Semi-circle Area: %.2f", area);
}
                                                                                                                                            

$ cc area-of-semi-circle.c 
$ ./a.out 

Finds area of semi-circle
-------------------
Enter radius: 8
Semi-circle Area: 100.48