Just for fun. Of course the link @Werner gave you is a good start. Notice that what I did was just to play around with someone else's code. See MWE below:
Taking now the following code an playing around with the node anchors, we have the following MWE:
\draw[line cap=round](n.north west)--(n.south west)--(n.south east);
Note that this command may not be robust. So, wait for other possible responses and choose the best that suites your needs.