長さ

1. Origins, structure, and basic meaning

• Structure: 長さ is a noun read ながさ, formed from the adjective 長い plus さ to express measurable length.
• Basic usage: Use 机の長さを測る for measuring a dimension and 同じ長さに切る for cutting things to a target length.
  • 机の長さを巻き尺で測りました。 describes measuring the desk's length with a tape measure; 二本の紐を同じ長さに切ってください。 asks someone to cut two pieces of string to the same length.

2. Common pitfalls and similar expressions

• 長い and 長さ
  • 長い is an adjective describing something as long, while 長さ is the noun for the dimension being measured.
• 巻き尺で測る
  • で marks the tape measure as the tool used.
• 同じ長さに切る
  • に marks the target length produced by cutting.