Is the harbour bridge a truss bridge?

the rectangular things on the side are called trusses. so there for the "truss" bridge

yup

K Truss of course

The Sydney Harbour Bridge is an arch bridge. It is the largest steel arch bridge in the world, measuring 134 metres (429.6 ft) from top to water level, although it is not the longest. Up until 2006,...

No it isn't. It is a suspension bridge. Look it up!!