07. Area of Figures

#include <iostream>

using namespace std;

int main()
{
	string figure;
	cin >> figure;

	double area;
	if (figure == "square") {
		double a;
		cin >> a;
		area = a * a;
	}
	else if (figure == "rectangle") {
		double a, b;
		cin >> a >> b;
		area = a * b;
	}
	else if (figure == "circle") {
		double r;
		cin >> r;
		area = 3.141592654 * r * r;
	}
	else if (figure == "triangle") {
		double a, h;
		cin >> a >> h;
		area = a * h / 2.0;
	}

	cout.setf(ios::fixed);
	cout.precision(3);

	cout << area;
}