第四周——三角类2

#include<iostream>#include<Cmath>using namespace std;class Triangle{    private:    double a;    double b;    double c;    public:    void setA(double x)    {        a=x;    }    void setB(double y)    {        b=y;    }    void setC(double z)    {        c=z;    }    double getA()    {        return a;    }    double getB()    {        return b;    }    double getC()    {        return c;    }    bool isTriangle();    double perimeter();    double area();};int main(){    Triangle tri1;//定义三角形类的一个实例（对象）    double x,y,z;    cout<<"请输入三角形的三边：";    cin>>x>>y>>z;    tri1.setA(x);    tri1.setB(y);    tri1.setC(z);//为三边置初值    if(tri1.isTriangle())    {        cout<<"三条边为："<<tri1.getA()<<','<<tri1.getB()<<','<<tri1.getC()<<endl;        cout<<"三角形的周长为："<< tri1.perimeter()<<'\t'<<"面积为："<< tri1.area()<<endl;    }    else        cout<<"不能构成三角形"<<endl;    return 0;}bool Triangle::isTriangle(){    if(a+b<=c)    {        return 0;    }    else if(a+c<=b)    {        return 0;    }    else if(b+c<=a)    {        return 0;    }    else    {        return 1;    }}double Triangle::perimeter(){    return a+b+c;}double Triangle::area(){    double q,m;    q=(a+b+c)/2;    m=sqrt(q*(q-a)*(q-b)*(q-c));    return m;}