Some history cool

Why make it a pentagon shape?

The logic behind this was pretty simple — the site designated for construction was bordered by five roadways, so the developers decided to go with a five-sided building. Naturally, they called it the Pentagon.

An incredible amount of workers and materials brought it together.

The grounds and building went up in a stunning 16 months. The building was officially completed in January 1943, thanks to the help of 1,000 architects and 14,000 tradesmen who worked three shifts around the clock. A staggering amount of materials were needed, too, including:

• 435,000 yards of concrete
• 43,000 tons of steel
• 680,000 tons of sand and gravel

The first tenants moved into the building in April 1942, several months before the building was finished.