Here's a 3 footed, 3 cornered bowl made from spalted Ash . Approximately, it stands 11.5cm tall to the top 3 corner points and the widest diameter is 19.cm.

You can see it being made here on my YouTube channel: 
https://www.youtube.com/watch?v=8SwkEVCWRE0
 
The pieces I make are decorative/ornamental and are not waterproof or food safe.
 
Disclaimer:
Wood is a natural product - I cannot guarantee that there won't be further movement over time or depending on the environment it is in, to me this can enhance the piece, but I understand not everybody will like this.