[C++] 백준 3053번 : 택시 기하학

https://www.acmicpc.net/problem/3053

#define _USE_MATH_DEFINES

#include <iostream>

#include <math.h>

using namespace std;

int main() {

cout.setf(ios::fixed);

cout.precision(6);

double n;

cin >> n;

cout << n*n*M_PI << "\n";

cout << 2*n*n ;

}