Where will you find this type of arch in HK?

There is a fairly new building in Kowloon called The Arch. it's a residential building in Tsimshatsui. It does look like an arch from the outside.

Not sure about the Tsing Ma Bridge. Perhaps there is a similar landscape there w/ the bridge design.

by HK i thought you ment Hello Kitty...

*chortles with embarrassment*

I'm pretty much sure that your teacher is referring to the Hong Kong Convention and Exhibition Centre in Hong Kong Island area.

You can clearly see in here how it looks like...
http://www.travel-hongkong-attractions.com/images/Hong-Kong-Convention-and-Exhibition-Centre.jpg

tsing ma bridge is well..consisted of U shapes from the side..but i'm not sure if you'll say it's an arch?!

there's the building called the arch. and also the po lin monastery arch? even a small arch (kinda u-shaped) at Lai chi kok park

the source is a pic of the lai chi kok park arch