Conversation so far:
what's at the center of the pentagon
At the center of the Pentagon is a five-acre park that houses a now-closed hot dog stand.
how tall is the pentagon
The Pentagon building is 71 feet tall.
what did it cost to build the pentagon
It cost $83 million to build the Pentagon
where is the pentagon located
The Pentagon is located in Arlington County, Virginia, across the Potomac River from Washington, D.C.

Question: who were the architects of the building
Self-contained rewrite: who were the architects of the Pentagon