- 圓的基本用語 Basic term of Circle
- 弦 Chord of a circle
- 弦與圓心的距離 Distance between Chords and Centre
- 圓的角 Angles in a circle
- 弧、弦和角的關係 Relationship among Arcs, Chords and Angles
- 弧長與角度成正比 Arcs Proportional to Angles
- 圓內接四邊形 Cyclic Quadrilaterals
- 共圓點的測試 Test for Concyclic Points