Final answer:
Hitler gained territory between 1930 and 1938 through military aggression, political negotiations, and the invasion of Poland in 1939.
Step-by-step explanation:
Between 1930-1938, Hitler gained territory primarily through military aggression and political negotiations.
Initially, Hitler began to rebuild German military strength by withdrawing Germany from the League of Nations and violating the provisions of the Treaty of Versailles. He sent troops into the Rhineland and initiated the annexation of Austria in 1938. Hitler also used intimidation and political pressure to negotiate the Munich Pact, which allowed Germany to occupy the Sudetenland and later the rest of Czechoslovakia.
Furthermore, Hitler launched a full-scale invasion of Poland in 1939, which marked the beginning of World War II.