What are three ways a state's boundary be changed?

A state's boundary can be changed through several methods, including:

1. Legislation: State legislatures or Congress may pass laws to alter boundaries, often requiring agreements between affected states.
2. Judicial Decisions: Courts can resolve disputes over boundaries, leading to changes based on legal rulings.
3. Referendums: Voter approval can lead to boundary changes, especially if local populations desire to join adjacent states or create new political divisions.