Okay, the user wants me to translate "quarter-circle" into Finnish. Let me think. The term "quarter-circle" refers to a quarter of a circle, which is 90 degrees. In Finnish, "quarter" is "neljännes" and "circle" is "ympyrä". So combining them, it should be "neljännesympyrä". Let me check if that's the correct term. Sometimes, hyphenation might be needed, but in Finnish, compound words are often written without a hyphen. For example, "neljännesympyrä" is a common term. I don't think there's a different way to say it. Also, the user mentioned if the content is already in Finnish, leave it as is. Since the original is in English, translating to Finnish is correct. No explanations needed, just the translation. So the answer is "neljännesympyrä".