1. The first example is an instance of dramatic irony, where Romeo's statement of love for Tybalt is the opposite of what the audience knows to be true.
2. The second example is an instance of situational irony, where the very thing the families were fighting over, their honor, led to the death of their children.
3. The third example is an instance of verbal irony, where Juliet says the opposite of what she means, and the audience knows that she loves Romeo, not Paris.