We can use dimensional analysis to convert from degrees to arcminutes, then from arcminutes to arcseconds:
#color(white)=1^@#
#=1^@*"60 arcminutes"/1^@#
#=color(red)cancelcolor(black)(1^@)*"60 arcminutes"/color(red)cancelcolor(black)(1^@)#
#="60 arcminutes"color(white)*#
#="60 arcminutes"*"60 arcseconds"/"1 arcminute"#
#="60"color(red)cancelcolor(black)"arcminutes"*"60 arcseconds"/("1"color(red)cancelcolor(black)"arcminute")#
#=60*"60 arcseconds"/1#
#=60*"60 arcseconds"#
#="3600 arcseconds"color(white)*#