I love these triangle-shaped buildings, set on odd shaped corners.  The Flatiron is the most famous such building, and apparently derived its name from the resemblance of its shape to that of a clothing iron.  In Manhattan north of 14th Street, most such buildings will occur, like the Flatiron, at an intersection where Broadway crosses one of the avenues, as I discussed in this post.  South of 14th Street, however, the streets are a maze with no grid pattern, so there are a lot more buildings that look something like this one.