梯てい形けい

noun, noun which may take the genitive case particle 'no'

trapezoid; trapezium

Geometric term for a quadrilateral with at least one pair of parallel sides. The spelling 梯形 is now rare; modern Japanese uses 台形.

See also: 台形

• 古ふるい教きょう科か書しょでは「梯てい形けい」と書かかれているが、今いまは「台だい形けい」が普ふ通つうだ。

  In old textbooks it is written as 梯形, but now 台形 is the usual form.