対角線(たいかくせん)

たいかくせん
noun
diagonal (of a polygon); diagonal line
1. diagonal (of a polygon)
a line segment connecting two non-adjacent vertices of a polygon
正方形(せいほうけい)の対角線(たいかくせん)を引(ひ)く。
To draw the diagonal of a square.
長方形(ちょうほうけい)の対角線(たいかくせん)の長(なが)さを計算(けいさん)する。
To calculate the length of the diagonal of a rectangle.
六角形(ろっかくけい)には九本(きゅうほん)の対角線(たいかくせん)がある。
A hexagon has nine diagonals.

対角線(たいかくせん) is a line segment connecting two non-adjacent vertices (corners) of a polygon.

KANJI BREAKDOWN:

  • 対(たい): opposite, facing
  • 角(かく): angle, corner
  • 線(せん): line

MATHEMATICS:
The number of diagonals in a polygon with n sides is n(n-3)/2. For example, a square has 2 diagonals, a hexagon has 9.

COMMON EXPRESSIONS:

  • 対角線(たいかくせん)を引(ひ)く: to draw a diagonal
  • 対角線(たいかくせん)の長(なが)さ: length of a diagonal
  • 対角線(たいかくせん)で分(わ)ける: to divide by a diagonal

RELATED TERMS:

  • 斜線(しゃせん): diagonal/slanted line (general)
  • 対角(たいかく): diagonal; opposite corners
  • 頂点(ちょうてん): vertex
general
Added 2026.1.25 14:57 · Revised 2026.1.28 11:20
08000/08121_taikakusen