Okay, the user wants me to translate "quarter-circle" into Italian. Let me think. The term "quarter-circle" refers to a quarter of a circle, which is 90 degrees. In Italian, "quarter" is "quarto" and "circle" is "cerchio". So, "quarter-circle" would be "quarto di cerchio". I should check if there's a more common term. Sometimes, in geometry, they might use "settore circolare" for a circular sector, but that's more general. Since the user specified "quarter-circle", which is a specific type of sector, "quarto di cerchio" seems accurate. Also, the user mentioned if the content is already in Italian, leave it as is. Since the original is in English, I need to translate. I don't see any other possible translations. So the answer should be "quarto di cerchio".