While the street view of DC relating to significant points can appear to resemble a pentagram star, it in fact really is not. Look closer, lines (streets) are actually missing to complete the supposed pentagram. The total actual street design however is a series of central points- most with 5 radiating streets. So you actually can draw several 5 pointed stars correctly within the street plan, but since these do not tend to have any significant buildings at their points as does the incorrect star of conspiracy fame, they don't get any attention. Simple fact is it was a common design plan and still is based on nothing more than efficiency of movement within a grid.
Aside from that;
1- the pentagram is not a Masonic symbol, it has no meaning or symbolic value within Masonry.
2- Historically, the pentagram has a long history of cultural and religious use (even in the Christian faiths) that debunk its supposed sinister nature many think of today.
3- "Baphomet", the made up creature/deity which Phillip of France invented as part of the persecution of the Templar Knights has no relationship to Masonry, and was never associated as being related to the pentagram until the late 1800's when the artist Levi was commissioned to create an illustration relating the two as part of the Taxil hoax.
4- the man who laid out the street design of DC, Pierre L’Enfant, was not a Mason, Prince Hall or otherwise, and would have no reason to insert symbolic values into a street plan. He simply laid out a grid similar to that which had been widely used in Europe since Roman times.
No relations, no significance, end of story.