ADD Circle,Line,Rectangle and Ellipse options in my minipaint app with C#

using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Paint
{
    public partial class Form1 : Form
    {
        Graphics Graphic;
        Pen p = new Pen(Color.Black, 2);
        Point ep = new Point(0, 0);
        Point sp = new Point(0, 0);


        int k = 0;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void panel1_Paint(object sender, PaintEventArgs e)
        {

        }

        private void pictureBox10_Click(object sender, EventArgs e)
        {
            p.Color = pinc.BackColor;
            recentcolor.BackColor = pinc.BackColor;
        }

        private void rose_Click(object sender, EventArgs e)
        {
            p.Color = rose.BackColor;
            recentcolor.BackColor = rose.BackColor;
        }

        private void blue_Click(object sender, EventArgs e)
        {
            p.Color = blue.BackColor;
            recentcolor.BackColor = blue.BackColor;
        }

        private void violet_Click(object sender, EventArgs e)
        {
            p.Color = violet.BackColor;
            recentcolor.BackColor = violet.BackColor;
        }

        private void yellow_Click(object sender, EventArgs e)
        {
            p.Color = yellow.BackColor;
            recentcolor.BackColor = yellow.BackColor;
        }

        private void green_Click(object sender, EventArgs e)
        {
            p.Color = green.BackColor;
            recentcolor.BackColor = green.BackColor;
        }

        private void red_Click(object sender, EventArgs e)
        {
            p.Color = red.BackColor;
            recentcolor.BackColor = red.BackColor;
        }

        private void orange_Click(object sender, EventArgs e)
        {
            p.Color = orange.BackColor;
            recentcolor.BackColor = orange.BackColor;
        }

        private void white_Click(object sender, EventArgs e)
        {
            p.Color = white.BackColor;
            recentcolor.BackColor = white.BackColor;
        }

        private void black_Click(object sender, EventArgs e)
        {
            p.Color = black.BackColor;
            recentcolor.BackColor = black.BackColor;
        }


        private void button4_Click(object sender, EventArgs e)
        {
            Close();             // Exit 
        }

        private void button3_Click(object sender, EventArgs e)
        {
            pictureBox1.Image = null;  // Clear Image

        }

        private void button2_Click(object sender, EventArgs e)
        {
            pictureBox1.Refresh();
            using (var bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height))
            {
                pictureBox1.DrawToBitmap(bmp, new Rectangle(0, 0, bmp.Width, bmp.Height));
                bmp.Save(@"c:\test.png");
            }

        }

        private void pictureBox1_MouseDown_1(object sender, MouseEventArgs e)
        {
            sp = e.Location;
            if (e.Button == MouseButtons.Left)
                k = 1;
        }

        private void pictureBox1_MouseUp_1(object sender, MouseEventArgs e)
        {
            k = 0;
        }

        private void pictureBox1_MouseMove_1(object sender, MouseEventArgs e)
        {
            if (k == 1)
            {
                ep = e.Location;

                Graphic = pictureBox1.CreateGraphics();
                Graphic.DrawLine(p, sp, ep);
                sp = ep;

            }
        }

    }
}