Which of these persuasive techniques can be used in a formal letter to build an argument?

When writing a letter, layout and paragraphs are important factors. A writer always addresses an audience, which, of course, means the reader. When someone writes a letter, this relationship between reader and writer becomes less abstract and much more immediate. A letter is often meant for a single person. At high school, you will be required to know how to write letters for several purposes, using different styles.