求发一下代码，多谢了

求发一下这道题的代码，实在是不太懂敲得出了，想跟各位学习一下，谢谢了~！

#include <iostream>
using namespace std;
class Triangle
{
    private:
        float a,b,c;
    public:
        Triangle(int a1=8,int b1=7,int c1= 6) : a(a1),b(b1),c(c1) {}
        float Perim() {return a+b+c;}
        ~Triangle() {cout<<a<<endl;}
};
int main()
{
    Triangle t1(3,4,5),t2(4,5),t3(5),t4;
    cout<<"t1的周长：" <<t1.Perim()<<endl;
    cout<<"t2的周长：" <<t2.Perim()<<endl;
    cout<<"t3的周长：" <<t3.Perim()<<endl;
    cout<<"t4的周长：" <<t4.Perim()<<endl;
    return 0;
}

#include <iostream>
#include<string>
#include<cmath>
using namespace std;
class Triangle
{
private:
    int x,y,z;
public:
    void printarea();
    void printperimeter();
    Triangle(int a,int b,int c);
};
Triangle::Triangle(int a,int b,int c){
    x=a;
    y=b;
    z=c;
}
//计算面积
void Triangle::printarea()
{
    float p;
    p=(x+y+z)/2;
    cout<<"三角形的面积为：";
    cout<<sqrt(p*(p-x)*(p-y)*(p-z))<<endl;
}
void Triangle::printperimeter(){
    cout<<"三角形的周长为：";
    cout<<x+y+z<<endl;
}
 
int main()
{
    Triangle t(1,2,3);
    t.printarea();
    t.printperimeter();
}