One standard size for the United States flag is 19 feet by 10 feet. On a flag of this size, the union (the blue rectangle in the top-left corner) is feet by feet. There are many places that display flags of different sizes. Many classrooms display a U. S. flag . Flags are often displayed on stamps. There was a flag on the space shuttle. Astronauts on the Apollo missions had a flag on a shoulder patch. Choose one of the four options and decide on a size that would be appropriate for this flag. Find the size of the union.