Anger(愤怒) is a kind of feeling. Many things can make you angry. When your teacher gives you too much homework, when your team loses an important game, when a friend borrows your favorite thing and then breaks it, you may get really angry.
Usually, your body will tell you when you are angry. For example, you breathe faster, your face turns red, and you may want to break something or hit(打) someone, but sometimes, you hide(隐藏) your anger. For example, you may hide it in your heart. The problem is that if you do this, you may get a headache or your stomach may hurt.
In fact, it's not good to hide your anger, and it's normal for you to get angry sometimes. But anger must be let out in the right way, without hurting others or yourself.
When you get angry, you can talk about it with other people. It's helpful to talk about your anger with an adult, such as parents, a teacher, etc. When you talk about anger, those bad feelings can start to go away. Here are some other things you can do when you start to feel angry: talk to a good friend; count from 1 to 100; give someone a hug(拥抱); go for a bike ride; think about good things, etc.
Remember that how you act when you are angry can make everything better or worse. Don't let your anger control you.