I just looked it up and found this (below). Apparently, in Italy, all, or most, pizza isn’t served pre-sliced. So one one HAS to cut it up themselves. It’s also apparently of a different type: long uncut rectangle
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The waiter heads your way with a beautiful margherita pizza in hand. He puts it in front of you and you notice that it isn’t sliced, what now? Italians eat pizza with a fork and knife.
Pizza is to be enjoyed straight from the oven and piping hot. Waiting for your dinner to cool down is just not an option – protocol says it should be enjoyed straight away. Therefore, if you grab a hot slice you’re begging for a burn. Just cut it up with the knife and fork and spare yourself the inevitable pain. ...”
No, it’s typically round, at least in my experience. Definitely uncut, though.