Math errors in a basic C ++ program

Question

I am working with a basic C ++ program to determine the area and perimeter of a rectangle. My program works fine for integers, but it falls apart when I use any number with a decimal point. I get the impression that I'm leaving something, but since I'm a complete beginner, I have no idea what.

Below is the source:

#include <iostream> using namespace std; int main() { // Declared variables int length; // declares variable for length int width; // declares variable for width int area; // declares variable for area int perimeter; // declares variable for perimeter // Statements cout << "Enter the length and the width of the rectangle: "; // states what information to enter cin >> length >> width; // user input of length and width cout << endl; // closes the input area = length * width; // calculates area of rectangle perimeter = 2 * (length + width); //calculates perimeter of rectangle cout << "The area of the rectangle = " << area << " square units." <<endl; // displays the calculation of the area cout << "The perimeter of the rectangle = " << perimeter << " units." << endl; // displays the calculation of the perimeter system ("pause"); // REMOVE BEFORE RELEASE - testing purposes only return 0; } 

Answer 1

Change all variables of type int to double or float . I personally would use double , because they have more precision than float types .

Answer 2

int datatype means an integer (i.e. positive and negative integers, including 0)

If you want to represent decimal numbers, you will need to use float.

Answer 3

Use a float or double type, like the others already mentioned.

But it is not so simple. You need to understand what floating point numbers are and why (0.1 + 0.1 + 0.1)! = (0.3). This is a difficult question, so I won’t even try to explain it here - just remember that the float is not decimal, even if the computer displays it to you as decimal.

Answer 4

use float not ints integer (int) - an integer, float allows decimal places (like doubles)

 float length; // declares variable for length float width; // declares variable for width float area; // declares variable for area float perimeter; // declares variable for perimete 

Answer 5

You defined the variables as integers. Use double instead.

In addition, you can find some formatting for cout to determine the number of decimal places you want to show, etc.