Rysowanie prostokątów

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace RysowanieProstokatow2
{
public partial class Form1 : Form
{
Graphics g1;
public Form1()
{
InitializeComponent();
g1 = this.CreateGraphics();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void Button1_Click(object sender, EventArgs e)
{
}
private void Button1_Click_1(object sender, EventArgs e)
{
}
private void Button1_Click_2(object sender, EventArgs e)
{
Pen p1 = new Pen(Color.Blue, 3);
g1.DrawRectangle(p1, 10, 100, 100, 60);
}
private void Button2_Click(object sender, EventArgs e)
{
SolidBrush b1;
b1 = new SolidBrush(Color.Aqua);
g1.FillRectangle(b1, 120, 100, 200, 100);
}
private void Button3_Click(object sender, EventArgs e)
{
Pen p1 = new Pen(Color.Red, 3);
g1.TranslateTransform(400, 100);
for (int i = 1; i <= 5; i++)
g1.DrawRectangle(p1, i * 10, i * 5, 300 - i * 20, 200 - i * 10);
}
}
}