The Pentagon
0Loading crowd target
0Loading crowd target
6correct to beat the crowd
40 free The Pentagon trivia questions with answers — history quiz, new questions added Oct 2026.
The Pentagon is one of the most recognisable buildings on Earth and one of the least understood. Almost everyone can picture its five-sided outline from the air, yet few people know why it has that shape, how quickly it went up, or what the builders had to improvise because the country was arming for a world war. Its story takes in presidents, generals, architects, protesters and a few very strange Cold War rumours. This quiz covers the building from the first sketches to the present day: the choice of site and the race to finish it, the layout of its corridors and offices, the people who designed and ran it, the antiwar demonstrations of the 1960s and 1970s, the leaked Vietnam study that borrowed its name, and the attack of September 11, 2001, along with the rebuilding and remembrance that followed. A couple of questions look at the word itself and at how the place compares with other famous buildings. It suits history buffs, military families, students of government, visitors planning a tour of Washington, and quiz hosts who want a themed round. Every answer comes with a short explanation, so you will finish knowing more than when you started.
30 of 40 questions with answers and explanations. Play the quiz
Q 01After overseeing the Pentagon's construction, Leslie Groves took charge of which secret wartime program in 1942?
Manhattan Project
Manhattan Project command came to him that September, and to avoid suspicion he kept supervising the building while secretly running the effort to make the atomic bomb.
Q 02The Pentagon has Washington ZIP Codes, yet the building stands across the river from the capital in which state?
Virginia
Virginia is its home, in Arlington County, yet the building has six ZIP Codes that all belong to the capital.
Q 03The sand used to build the Pentagon, hundreds of thousands of tons of it, was dredged from which nearby river?
Potomac
Potomac sand went into the building's reinforced frame, and the dredging left a lagoon beside the river entrance.
Q 04What happened at the Pentagon's building site on September 11, 1941, exactly 60 years before the 2001 attack?
Ground was broken
Ground was broken on the very day the construction contracts were finalized, about three months before the attack on Pearl Harbor added urgency to the job.
Q 05During the Cold War, the Soviets reportedly thought which structure in the Pentagon's courtyard hid a bunker entrance?
A hot dog stand
A hot dog stand drew the suspicion because officers were seen going in and out at the same time each day, and the legend earned it the nickname Cafe Ground Zero.
Q 06The Pentagon was built with twice as many restrooms as its workforce needed because of what 1940s state requirement?
Racial segregation
Racial segregation was state law, but a presidential order had banned discrimination against federal workers, so it became the one building in the state where those laws were not enforced.
Q 07Which president moved the Pentagon's planned site so it would not block the view from Arlington National Cemetery?
Franklin Roosevelt
Franklin Roosevelt picked another site nearby and kept the five-sided plan, partly because he liked it and partly because a redesign at that stage would have been costly.
Q 08In a famous 1967 photograph taken at the Pentagon, a protester places which flowers into soldiers' rifle barrels?
Carnations
Carnations fill the barrels in Flower Power, a picture Bernie Boston's editor buried deep inside the newspaper before it went on to win photography competitions.
Q 09At the 1967 March on the Pentagon, what did activist Abbie Hoffman vow to do to the building using psychic energy?
Levitate it
Levitate it until it turned orange and began to vibrate, he claimed, at which point the war in Vietnam would end.
Q 10Why were only about 800 people, rather than the usual 4,500, in the part of the Pentagon struck in 2001?
Renovation work
Renovation work had emptied most of the offices, and the nearly finished job had added steel reinforcement that kept that section standing for 30 minutes while hundreds of people got out.
Q 11Which hijacked airliner was flown into the western side of the Pentagon at 9:37 a.m. on September 11, 2001?
Flight 77
Flight 77 was a Boeing 757 whose crash started a fire that took several days to put out; all 64 people aboard and 125 people inside the building were killed.
Q 12The hijacked airliner that struck the Pentagon in 2001 had taken off at 8:20 that morning from which airport?
Dulles International
Dulles International was 31 minutes behind the jet when the hijackers stormed the cockpit and forced the passengers and crew to the rear of the cabin.
Q 13The 2001 strike on the Pentagon was the first major foreign attack on the capital area since which conflict?
War of 1812
Q 21To save metal for the war effort, the Pentagon's builders linked its floors with what instead of passenger elevators?
Concrete ramps
Concrete ramps carried people between floors for decades; until 2011, the lone passenger elevator was reserved for the defense secretary.
Q 22Which state supplied the limestone on the Pentagon's outer walls, a stone also used for the Empire State Building?
Indiana
Indiana limestone faces the building, and another 15,000 cubic feet of it was used to rebuild the section destroyed in 2001.
Q 23The Pentagon rose on land once home to what facility, considered one of the most hazardous of its kind in America?
An airfield
War of 1812 fighting brought British troops to Washington in 1814, where they burned the White House and other public buildings.
Q 14At the Pentagon Memorial, the 184 benches for those killed there in 2001 are arranged in order of what?
The victims' ages
The victims' ages run from 3 to 71, and each bench also shows by its direction whether that person died inside the building or aboard the plane.
Q 15What name was given to the push to rebuild the Pentagon's wrecked section within a year of the 2001 attack?
Phoenix Project
Phoenix Project crews beat their deadline, with staff moving back into the rebuilt outer offices on 15 August 2002, nearly a month early.
Q 16Which secretary of defense held a press conference inside the damaged Pentagon on the evening of the 2001 attack?
Donald Rumsfeld
Donald Rumsfeld told reporters that the building was still functioning and would be in business the next day.
Q 17Which novelist won a Pulitzer Prize for The Armies of the Night, his account of the 1967 March on the Pentagon?
Norman Mailer
Norman Mailer set out to get himself arrested at the march, then described his night in custody in the third person.
Q 18Which radical group set off a bomb in a Pentagon women's restroom in May 1972, on Ho Chi Minh's birthday?
Weather Underground
Weather Underground bombers caused flooding that destroyed computer tapes holding classified information, in what the group called retaliation for American raids on Hanoi.
Q 19Which former analyst leaked the secret Vietnam War study known as the Pentagon Papers to the press in 1971?
Daniel Ellsberg
Daniel Ellsberg had worked on the study himself, and the charges against him were dismissed after wrongdoing by Nixon White House staff came to light.
Q 20Which secretary of defense commissioned the secret Vietnam War history that later became known as the Pentagon Papers?
Robert McNamara
Robert McNamara set up the task force in June 1967, and its 36 analysts filled 47 volumes that were finished only after he had left office.
An airfield with short, unpaved runways and a smoking garbage dump nearby operated here until 1941, when the government bought the land for $1 million.
Q 24The corridors running through all five floors of the Pentagon add up to roughly what total length?
17.5 miles
17.5 miles of corridors and 7,754 windows fill the building, yet ten spoke-like hallways cutting across the rings keep any two points within a few minutes' walk.
Q 25With crews working around the clock, roughly how long did it take to build the entire Pentagon during World War II?
16 months
16 months was all it took, and office space was so short that the first staff moved in long before the rest of the building was finished.
Q 26A diamond exchange in which Indian city took the Pentagon's long-held title of world's largest office building in 2023?
Surat
Surat Diamond Bourse, made up of nine interconnected 15-floor towers, was declared the record holder by Guinness World Records in August 2023.
Q 27The Hall of Heroes on the Pentagon's main concourse is dedicated to the recipients of which military decoration?
Medal of Honor
Medal of Honor recipients are listed by name in the hall, which opened in 1968 and displays the Army, Sea Service and Air Force versions of the medal.
Q 28The Moscow hotline, whose American end sits in the Pentagon, was never a red telephone; what did it first use?
Teletype machines
Teletype machines carried the first messages, encrypted with one-time pads, and test transmissions have included passages from Shakespeare and Chekhov.
Q 29Which California architect drew up the Pentagon's design in July 1941 but resigned before the building was finished?
George Bergstrom
George Bergstrom stepped down in April 1942 after misconduct charges linked to his presidency of the American Institute of Architects, and David Witmer finished the job.
Q 30Which Army construction chief gave his designers a single weekend in July 1941 to draw up plans for the Pentagon?
Brehon Somervell
Brehon Somervell asked for a modern four-story building with no elevators, and he is buried in the national cemetery nearby, not far from what was called his brain child.