Final answer:
Hitler took action against Jewish people in Germany by building ghettos for them in many cities.
Step-by-step explanation:
During the 1930s, Hitler took action against Jewish people in Germany by building ghettos for Jewish people in many cities. Jewish people were forced to live in overcrowded and sealed areas, where they faced starvation, disease, and despair. These ghettos were a way for the Nazis to control the Jewish population before they were later sent to concentration camps.