计算三角形面积（异常处理）

问题本身很简单，贴这个代码主要是想强调一下里面涉及到的异常处理

#include<iostream>
#include<cmath>
#include<stdexcept>
using namespace std;

double area(double a, double b, double c) throw (invalid_argument)
{
	if (a <= 0 || b <= 0 || c <= 0)
		throw invalid_argument("the side length should be positive");
	if (a + b <= c || b + c <= a || a + c <= b)
		throw invalid_argument("the side length should fit the thriangle inequation");
	double s = (a + b + c) / 2;
	return sqrt(s*(s - a)*(s - b)*(s - c));
}
int main()
{
	double a, b, c;
	cout << "please input the side length of thriangle:" << endl;
	cin >> a >> b >> c;
	try
	{
		double s=area(a, b, c);
		cout << "Area:" << s << endl;
	}
	catch (exception &e)
	{
		cout << "Error:" << e.what() << endl;    //what()是Exception基类中的一个成员函数，用于返回错误信息
	}
    return 0;
}