An Enneagram type 1 is one of nine personality types. It is commonly called the perfectionist or reformer. Type 1 is focused on doing things correctly and behaving appropriately according to an internalized sense of what's right.
Enneagram type 1 can struggle with being overly critical of themselves and others as well as becoming too rigid and nonadaptable in their perfectionistic tendencies.
Enneagram type 1 believes that people should know what's right and act accordingly. They get angry when people don't live up to that. They may not show that anger outright if they believe anger is not an acceptable emotion to have.