対たい心しん

Meanings

1

noun-modifying (irregular)

Technical term in geometry, describing points on a sphere that are diametrically opposite. Used attributively before nouns.

球きゅう面めん上じょうの対たい心しん点てんを結むすぶ線せんは直ちょっ径けいになる。
A line connecting antipodal points on a sphere becomes a diameter.