Bing found the following results
The Pentagon - Wikipedia
U.S. Department of Defense
Pentagon - Location, Building Timeline, 9/11 - HISTORY
Pentagon History: 7 Big Things to Know - U.S. Department of Defense
Pentagon | History & Features | Britannica
10 Things You Probably Didn't Know About the Pentagon
Why Is the Pentagon a Pentagon? | Smithsonian
Pentagon summary | Britannica
Historical Office > DOD History > Pentagon > History
‘We’re Going to Publish’: An Oral History of the Pentagon Papers