Yes, the pupil can dilate when people get angry. Actually there are some reasons for pupil dilated. The most common reason is the dark environment. The pupil works like a camera aperture. In the dark environment, it dilated to get more light into eyes so that people could see more and clearer. Yet there are still some other reason for dilated pupil, for example, drugs, hormone oxytocin in blood, angry and fear.
Well, in my opinion, if you are angry, it can lead to dilated pupils. Generally speaking, there are many factors which can cause dilated pupils. For example, high blood pressure can be the cause. When you are angry, your blood pressure can be high, and then it can lead to dilated pupils. And you also should know that when you are too tired, it is easy for you to have high eye pressure. When you have eye pressure, it can make the black part of the eye bigger than normal. And then it leads to dilated pupils. By the way, anxiety can cause it too. so just be careful about it.
Yes, when you feel angry, your pupils will get dilated. It is normal. In addition, when you are surprising and shocked, you will find that your eyes get dilated too. However your eyes will get recovery at the normal size after a while. It is the normal physical reaction. However, too long time of dilated eyes will make your eyes get dry and may get the invisible bacterium.