The moniker "flatiron" comes from this shape of building being very similar to an actual 19th century flat iron.

This one is located on the triangular intersection between Plymouth Avenue and Second Street.

I am not sure if this is a "true" flat iron building. But it's pretty close. Below I show you an aerial view of it so you can see what I mean.

This next one is in the downtown area on the intersection between Hartwell street and 4th street.