(subclass TwoDimensionalAngle OpenTwoDimensionalFigure) | Merge.kif 17805-17805 | 子類 二維角度 and 開放二維圖 |
(subclass ObliqueAngle TwoDimensionalAngle) | Mid-level-ontology.kif 4844-4844 | 子類 斜角 and 二維角度 |
(subclass RightAngle TwoDimensionalAngle) | Mid-level-ontology.kif 4855-4855 | 子類 直角 and 二維角度 |
(subclass AcuteAngle TwoDimensionalAngle) | Mid-level-ontology.kif 4863-4863 | 子類 銳角 and 二維角度 |