Are Any of NYC's "Square" Parks Actually Square?

From Times Square to Washington Square Park, most of the "squares" around the city aren't quite mathematically perfect. Whether they're rectangles, triangles, or other squished-up trapezoids, most of NYC's parks don't measure up to a geometric definition of "square".
While visiting New York, Matt Parker of standupmaths.com took a tour around the city and put our parks to the test, finding which public squares were the most equilateral.
Think of a few "square" parks – can you guess which one Matt finds to be the most square?