円弧

1. Origins, structure, and basic meaning

• Structure: 円弧 is read as えんこ and is a noun for an arc, a curved segment forming part of a circle's circumference.
• Basic usage: Drawing a smooth arc on paper appears in 紙に滑らかな円弧を描く, while a bridge forming a gentle arc appears in 橋が緩い円弧を成す.

2. Common pitfalls and similar expressions

• Difference from 円
  • 円 refers to the complete closed circle, whereas 円弧 refers to one continuous portion of its circumference.