Some of the lines look squiggly, but I would say the ones ones on the Chrysler building are probably straight edge (and there’s no problem using a striaght for crisp lines).

>Very nice. How did you make the vertical lines so straight while freehand?

thank you ! I have been practicing for a long time and my hand is quite steady for tracing. As this drawing is not big (A4 size) it is not complicated for me to do without using rulers. But I don't see any problem in using it and I would say it if I had used.