C Programming Code Examples C > Mathematics Code Examples C Program for Beginners: Area of Circle C Program for Beginners: Area of Circle Ellipse in which the two axes are of equal length Plane curve generated by one point moving at a constant distance from a fixed point You can compute the area of a Circle if you know its radius. #include<stdio.h> int main() { float radius, area; printf("\nEnter the radius of Circle : "); scanf("%d", &radius); area = 3.14 * radius * radius; printf("\nArea of Circle : %f", area); return (0); }