刚入门，这种难度自己写起来有点费力

#include<iostream>
#include<cmath>
using namespace std;
class Point {
    float x;
    float y;

public:
    Point()   //显示定义一个默认构造函数
    {
        x = 0;
        y = 0;
    }
    Point(float x, float y) {
        this->x = x;
        this->y = y;
    }
    float getx() {
        return x;
    }
    float gety() {
        return y;
    }
};
class Rectangle {
    Point TopLeft;
    Point RightBottom;
public:
    Rectangle() {
        TopLeft = Point();
        RightBottom = Point();
    }
    Rectangle(float tlx, float tly, float rbx, float rby) {
        TopLeft = Point(tlx, tly);
        RightBottom = Point(rbx, rby);
    }
    double Area() {
        return abs((TopLeft.getx() - RightBottom.getx()) * (TopLeft.gety() - RightBottom.gety()));
    }
    double Perimeter() {
        return (abs(TopLeft.getx() - RightBottom.getx()) * 2 + abs((TopLeft.gety() - RightBottom.gety())* 2));
    }
};
int main() {
    float tlx, tly, rbx, rby;
    Rectangle rectangle;
    cout << "请输入左上点x坐标:";
    cin >> tlx;
    cout << "请输入左上点y坐标:";
    cin >> tly;
    cout << "请输入右上点x坐标:";
    cin >> rbx;
    cout << "请输入右上点y坐标:";
    cin >> rby;
    rectangle = Rectangle(tlx, tly, rbx, rby);
    cout << "周长:" << rectangle.Perimeter() << "面积:" << rectangle.Area() << endl;
}

没细测