正方形

• Reading: せいほうけい
• Romaji: seihoukei
• Kanji breakdown: 正 (sei) — correct, regular; 方 (hou) — side, direction; 形 (kei) — shape, form
• Pronunciation: /seː.hoː.keː/

Meaning

Square; a four-sided figure with equal sides and right angles.

A noun and no-adjective for the geometric shape 'square.' Used in mathematics, design, architecture, and daily life. Related terms: 長方形 (chouhoukei, rectangle), 三角形 (sankakkei, triangle), 円 (en, circle). Functions as a no-adjective: 正方形の紙 (square paper). Also used metaphorically for things that are perfectly square-shaped.

Examples

1. 折り紙は正方形の紙を使います。 Origami uses square pieces of paper.
2. この部屋はほぼ正方形の形をしている。 This room is almost perfectly square.
3. 正方形の面積は一辺の長さの二乗で求められる。 The area of a square is found by squaring the length of one side.

Usage Guide

Context: mathematics, design, crafts

Tone: neutral

Origin & History

From Chinese, combining 正 (correct, regular), 方 (direction, side), and 形 (shape, form). Literally 'correct-sided shape' — a shape where all sides are equal and proper. The compound mirrors the mathematical precision of the figure it names.

Cultural Context

Era: Classical

Generation: All ages

Social background: Universal