Here's why:
* You are attempting to change the teacher's mind. Instead of simply accepting the deadline, you are using arguments, logic, or appeals to emotion to convince them to extend it.
* You are using communication skills. You are likely communicating your reasons for needing an extension clearly and respectfully.
* You are aiming for a specific outcome. You want the teacher to agree to your request.
Of course, the success of your persuasion depends on many factors, like:
* Your reason for needing an extension. A valid and compelling reason is more likely to be successful than a vague or flimsy one.
* Your relationship with the teacher. A good relationship built on mutual respect might make them more likely to consider your request.
* The teacher's own policies and expectations. Some teachers are more flexible than others.
Overall, convincing your teacher to grant an extension is a classic example of using persuasion to achieve a desired outcome.