円周

1. Origins, structure, and basic meaning

• Structure: 円周 is read as えんしゅう and means “circumference”.
• Basic usage: The examples show a plate’s circumference measured with string and dots arranged around a circle.

2. Common pitfalls and similar expressions

• Distinguishing senses and uses
  • It is the boundary of a circle or its length, distinct from 面積, which measures the interior area.