2067: [example 2.5] circle

2067：【 example 2.5】 round

The time limit : 1000 ms         Memory limit : 65536 KB
Submission number : 27674     Passing number : 14895

【 Title Description 】

Enter the radius r, The diameter of the output circle 、 Perimeter 、 area , Numbers are separated by a space , Keep each number after the decimal point 4 position .

【 Input 】

Enter the radius .

【 Output 】

As stated in the title . Numbers are separated by a space .

【 sample input 】

1.0

【 sample output 】

2.0000 6.2832 3.1416

#include<iostream>
#include<cmath>
#include<iomanip>
using namespace std;
int main()
{
	float r, d, c,PI=3.1415926, s;
	cin >> r;
	d = 2 * r;
	c = 2* PI * r;
	s = PI * r * r;
	cout << setiosflags(ios::fixed) << setprecision(4) << d << " " << c << " " << s;
    return 0;
}