From LivingPianos.

https://livingpianos.com/mastering-dotted-rhythms-in-beethovens-pathetique/

Welcome to LivingPianos.com. I’m Robert Estrin, and today I’m responding to a great viewer question. Someone asked if I could do an updated explanation of dotted rhythms, specifically using the first bars of Beethoven’s Pathétique Sonata as an example. They mentioned still struggling to count the dotted rhythms there—and frankly, I understand. You’d be surprised how many performances of the Pathétique have imprecise rhythm at the opening!