These conspiracy theorist assholes always overlook all the other symbolism of the pentagon and pentagram.

The regular pentagon embodies the golden ratio in its construction. A dodecahedron (12 sided figure made of regular polygons) is a Platonic solid that signified the "essence" - the atomic element of life.

The pentagon used to be held in high regard as a symbol of beauty, intelligence, and divinity. And these Bible thumpers would know that if they knew anything about mathematics, history or mysticism (not the televised dog and pony show kind of "mysticism", either).