Knowledge: The highest waterfall in the world is Angel Falls, and it has a height of 3,212 feet. Niagara Falls is significantly shorter than Angel Falls.

Conversation:
Niagara Falls seems like a nice place to visit
Oh, yeah? I know it sits along the border between the US and Canada.
Yes, and they're really pretty.
That's nice. They also have about six million cubic feet of water going over them every minute, at least during peak tourist hours.
What is the height of Niagara Falls?

Response: It is hard to say, but I can tell you that Niagara Falls is significantly shorter than Angel Falls.