鈍角(どんかく)

どんかく
noun
obtuse angle
1. obtuse angle
An angle measuring more than 90 degrees but less than 180 degrees.
鈍角(どんかく)は90度(ど)より大(おお)きく180度(ど)より小(ちい)さい。
An obtuse angle is greater than 90 degrees and less than 180 degrees.
この三角形(さんかくけい)には鈍角(どんかく)が一(ひと)つある。
This triangle has one obtuse angle.
120度(ど)は鈍角(どんかく)だ。
120 degrees is an obtuse angle.

鈍角(どんかく) is a mathematical term for an obtuse angle (between 90° and 180°).

Writing

鈍(どん) (dull, blunt) + 角(かく) (angle, corner)

Angle classification

Triangle types by angle

Related math terms

角度(かくど) (angle measurement), 度(ど) (degree)

Related Words

Antonym: 鋭角(えいかく) (acute angle)
Antonym: 直角(ちょっかく) (right angle)
Related: 角度(かくど) (angle measurement)
Related: 平角(へいかく) (straight angle)
Compare: 斜角(しゃかく) (oblique angle)
general
Added 2026.1.16 17:11 · Revised 2026.9.2 12:02
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