$#doanthevu$

Code Bài 0 :

#include<bits/stdc++.h>
#define ll long long
using namespace std;
int main()
{
    ll a,b;
    cin>>a>>b;
    ll temp = a;
    a = b;
    b = temp;
    cout<<a<<" "<<b;
    return 0;
}

Code bài 1 :

#include<bits/stdc++.h>
#define ll long long
using namespace std;
int main()
{
    ll a,b,dt=0,cv=0;
    cin>>a>>b;
    dt = a*b;
    cv = (a+b)*2;
    cout<< " Dien tich : "<<dt<<endl;
    cout<<" Chu vi : "<<cv<<endl;
    return 0;
}

Code bài 2:

#include<bits/stdc++.h>
#define ll long long
using namespace std;
int main()
{
    double bk;
    double pi = 3.14159265358979;
    cin>>bk;
    double dt = pi * bk * bk;
    double cv = 2 * pi * bk;
    cout<<fixed<<setprecision(2)<< "Dien tich :  " << dt << endl;
    cout<<fixed<<setprecision(3)<< "Chu vi :  " << cv << endl;
    return 0;
}

Code bài 3 :

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

int main() {
    double a, b, c;
    cin>>a>>b>>c;
    double cv = a + b + c;
    double s = (a + b + c) / 2;
    double dt = sqrt(s * (s - a) * (s - b) * (s - c));
    cout<<fixed<<setprecision(1)<< "Dien tich :  "<<dt<<endl;
    cout<<fixed<<setprecision(3)<< "Chu vi : "<<cv<<endl;
    return 0;
}

// Bài 0: $\\$

#include <bits/stdc++.h>

using namespace std;

int main()

{

    int a, b, t;

    cout << "Nhap a: "; cin >> a;

    cout << "Nhap b: "; cin >> b;

    t = a;

    a = b;

    b = t;

    cout << "a = " << a << endl;

    cout << "b = " << b << endl;

    return 0;

}

$\\$$\\$

// Bài 1:$\\$

#include <bits/stdc++.h>

#define ll long long

using namespace std;

int main()

{

    ll a, b; cin >> a >> b;

    cout << "Dien tich: "<< a * b << endl; 

    cout << "Chu vi: "<< (a + b)*2 << endl;

    return 0;

}

$\\$$\\$

Bài 2:$\\$

#include <bits/stdc++.h>

using namespace std;

int main()

{

    double pi = 3.14159265358979;

    double r; cout << "Nhap ban kinh hinh tron: "; cin >> r;

    cout << "Dien tich: "<< fixed << setprecision(2) << pi*r*r << endl; 

    cout << "Chu vi: "<< fixed << setprecision(3) << 2*pi*r << endl;

    return 0;

}

$\\$$\\$

// Bài 3: $\\$

#include<bits/stdc++.h>

#define ll long long

using namespace std;

int main()

{

    double a, b, c; cin >> a >> b >> c;

    double C = a + b + c;

    double p = (a + b + c) / 2;

    double S = sqrt(p * (p - a) * (p - b) * (p - c));

    cout << fixed << setprecision(1) << "Dien tich : " << S << endl;

    cout << fixed << setprecision(1) << "Chu vi: " << C << endl;

    return 0;

}