Peterchen's pretzel

Peterchen's pretzel

Here is a simple problem for young people who find the other puzzles difficult.

Little Peterchen has a Vienna pretzel cookie as shown in the drawing and asks his young friends if they can guess how many parts it can be divided with a single straight knife cut.

I suppose it is a real pretzel in which both ends are not united, draw a straight line that can be seen in the maximum number of pieces.


The Pretzel can be divided into 10 parts as shown in the following illustration: