C++

#include<iostream>

using namespace std;

int main() {

        int a,b;

        cout << " Dien tich hinh chu nhat\n" ;

        cout << "Nhap 2 canh a,b: " ;

        cin >> a>>b;

        cout << "Dien tich hinh chu nhat : " <<a*b;

 Pascal

uses crt;

var a,b:real;

begin

          clrscr;

          write('nhap a,b');

          readln (a,b); 

          writeln ('Dien tich hinh chu nhat la: ', a*b);

          readln;

end.

C++:

#include <bits/stdc++.h>
using namespace std;

int main(){
    float a,b;

    cout << "Nhap chieu dai: "; cin >> a;
    cout << "Nhap chieu rong: "; cin >> b;

    float s = a * b;

    cout << "Dien tich hinh chu nhat: " << s;

    return 0;
}

Pascal:

uses crt;
var a,b:extended;
        s:real;
begin
        clrscr;
        write('Nhap chieu dai: '); readln(a);
        write('Nhap chieu rong: '); read(b);
        s:=a * b;
        writeln('Dien tich: ',s:0:2);
        readln
end.

Python:

a = float(input("Nhap chieu dai: "))
b = float(input("Nhap chieu rong: "))

print("Dien tich: ",a * b)