四角(しかく)

しかく
noun / na-adjective
square, rectangle
1. square, rectangle, quadrangle
A shape with four sides and four angles.
四角(しかく)い形(かたち)
A square shape.
[Note: 四角い is the i-adjective form]
四角(しかく)を描(か)く。
To draw a square.
正(せい)四角(しかく)形(けい)
A square (regular quadrilateral).
この箱(はこ)は四角(しかく)い形(かたち)をしているので、積(つ)み重(かさ)ねやすい。
This box has a square shape, so it's easy to stack.

四角(しかく) is a general term for any four-sided shape — squares, rectangles, and other quadrilaterals. It is the everyday word; for precise geometric terms, see below.

FORMS:

  • 四角(しかく) (noun): a square/rectangle
  • 四角(しかく)い (i-adjective): square-shaped, boxy — the most natural adjectival form
  • 四角(しかく)な (na-adjective): less common in everyday speech

PRECISE GEOMETRIC TERMS:

  • 正方形(せいほうけい): square (all sides equal)
  • 長方形(ちょうほうけい): rectangle
  • 四角形(しかくけい): quadrilateral (formal/mathematical)

RELATED SHAPES:

  • 三角(さんかく): triangle
  • 丸(まる): circle
  • 丸(まる)い: round (i-adjective)

USAGE:
In everyday conversation, 四角(しかく)い is used broadly to describe anything boxy or rectangular: 四角(しかく)い箱(はこ) (square box), 四角(しかく)い顔(かお) (square face).

general
Added 2026.1.11 18:01 · Revised 2026.2.15 22:14
02500/02836_shikaku