c++求梯形面积

#include<iostream>
using namespace std;
class TX
{
    private:
        double s1,s2,s3,area;
    public:
        TX(double a,double b,double h){
            s1=a;
            s2=b;
            s3=h;
        }
        void getarea()
        {
            area=(s1+s2)*s3 /2;
        }
        void outarea()
        {
            cout<<"梯形面积为"<< area << endl;
        }
};
int main(){
    double a,b,h;
    cout << "请输入梯形的上底：";
    cin >> a;
    cout << "请输入梯形的下底：";
    cin >> b;
    cout << "请输入梯形的高：";
    cin >> h;
    TX t1(a,b,h);
    t1.getarea();
    t1.outarea();
    return 0;
}