Showing Text in rich text box when button click

Hi all... simple question for you experts here!

I wanna show the following text in rich text box when button clicks,

I know how to show the text but I don't know how to split this single line into two lines

private void pictureBox2_Click(object sender, EventArgs e)
        {
            richTextBox1.Text = "My ApplicationDesigned by Prnv";

I wanna show the"Designed by prnv" in second line in the output

Pls sent reply with the code

Thanks for reading....