Okay, the user wants me to translate "quarter-circle" into French. Let me think. The term "quarter-circle" refers to a quarter of a circle, which is 90 degrees. In French, "quarter" is "quart" and "circle" is "cercle". So, "quarter-circle" would be "quart de cercle". I should check if there's a more common term. Maybe "quart de cercle" is correct. Let me confirm. Yes, in geometry, a quarter-circle is called "quart de cercle" in French. Since the original content isn't in French, I need to translate it. The user specified to provide only the translation without explanations. So the answer should be "quart de cercle".