计算图形面积和周长的界面设计c++

以下是一个简单的计算图形面积和周长的界面设计的C++代码示例：

#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    int choice;
    double radius, length, width, base, height, side, area, perimeter;

    cout << "1. Calculate the area and perimeter of a circle" << endl;
    cout << "2. Calculate the area and perimeter of a rectangle" << endl;
    cout << "3. Calculate the area and perimeter of a triangle" << endl;
    cout << "Enter your choice (1-3): ";
    cin >> choice;

    switch (choice)
    {
        case 1:
            cout << "Enter the radius of the circle: ";
            cin >> radius;
            area = M_PI * pow(radius, 2);
            perimeter = 2 * M_PI * radius;
            cout << "Area of the circle = " << area << endl;
            cout << "Perimeter of the circle = " << perimeter << endl;
            break;

        case 2:
            cout << "Enter the length and width of the rectangle: ";
            cin >> length >> width;
            area = length * width;
            perimeter = 2 * (length + width);
            cout << "Area of the rectangle = " << area << endl;
            cout << "Perimeter of the rectangle = " << perimeter << endl;
            break;

        case 3:
            cout << "Enter the base and height of the triangle: ";
            cin >> base >> height;
            area = 0.5 * base * height;
            cout << "Area of the triangle = " << area << endl;
            cout << "Enter the length of the side of the triangle: ";
            cin >> side;
            perimeter = base + 2 * side;
            cout << "Perimeter of the triangle = " << perimeter << endl;
            break;

        default:
            cout << "Invalid choice!" << endl;
            break;
    }

    return 0;
}

该代码使用了一个简单的菜单系统，允许用户选择要计算的图形类型。根据用户的选择，程序将要求用户输入必要的参数（例如，圆的半径，矩形的长度和宽度，三角形的底和高以及侧面长度），计算图形的面积和周长，并将结果输出到屏幕上。