How did the rise of dictatorships and the attack on pearl harbor cause the united states to become involved in world war 2?

The U.S. did not agree with what Hitler was doing in Germany but the U.S. was trying to stay out of it but then when the Japanese bombed Pearl Harbor of December 7, 1941 they didn't have a choice anymore and entered WWII and eventually brought the war to an end on August 6, 1945 by dropping a 5-ton atomic bomb on the city of Hiroshima.

Use the formula: (n-2)×180, where n is the number of sides(18-2)×180= 28800, now this is the full exterior angle of 18-gon so you divide it by 18.28800÷18=160