Monday, April 20, 2015

URI Online Judge | 1002 Area of a Circle


URI Online Judge | 1002

Area of a Circle

Adapted by Neilor Tonin, URI  Brazil
Timelimit: 1
The area of the circle is defined as A = π . R2, having π as 3.14159.
Calculate the area using the formula given in the problem description.

Input

Read the variable R (double precision), that is the radius of the circle.

Output

Print the variable A, rounded to four decimal digits.
Sample InputsSample Outputs
2.00A=12.5664
100.64A=31819.3103
150.00A=70685.7750


Solution:

#include <stdio.h>

int main()
{
    double r,pi=3.14159;
    scanf("%lf",&r);
    printf("A=%.4lf\n",pi*r*r);
    return 0;
}