C++返回错误的代码行

我被指示设计一种算法，允许用户计算矩形的周长和面积，但这太简单了：

Perimeter = 2 (Length + Width)
Area = (Length * Width)

我想使用与我的教授在第一天向我们展示的类似的结构来构建一个程序，以便我可以让一个程序从用户那里收集数据，为我计算矩形的周长和面积，然后将答案输出回用户。这很容易，所以我决定让程序也告诉我用户输入的长度和宽度是矩形还是正方形的长度和宽度。

使用我编写的代码，程序始终返回输入的长度和宽度是正方形的长度和宽度。我不确定我哪里出错了：

这是我的代码：

#include<iostream>
using namespace std;
int main() {
    //Declaration
    int length;
    int width;
    int perimeter;
    int area;
    //Collect Data
    cout << "Let's calculate the perimeter and area of a rectanglen";
    cout << "What is the length of the rectangle?: ";
    cin >> (length);
    cout << "What is the width of the rectangle?: ";
    cin >> (width);
    //Calculation
    (perimeter) = 2 * (length + width);
    (area) = (length) * (width);
    //Output Data
    cout << "The perimeter of the rectangle is: " << (perimeter) << "n";
    cout << "The area of the rectangle is: " << (area) << "n";
    //For some reason, the code is not able to recognize what I have designed.
    //No matter what input for length and width, when the program executes it returns that I entered the length and width of a square.
    if ((length) = (width))
        cout << "Hey! You entered the length and width of a Square!n";
    else
        cout << "You entered the length and width of a Rectangle!n";
    system("pause");
    return 0;
}

任何帮助将不胜感激！非常感谢！