Series Content LESSON 1 正弦/餘弦/正切 | Sine, Cosine and Tangent Ratios LESSON 2 根據三角比畫三角形 | Construct Triangles based on Trigonometric Ratios LESSON 3 特殊角的三角比 | Trigonometric Ratios of Special Angles LESSON 4 三角恆等式 | Trigonometric Identity LESSON 5 斜率 | Gradients LESSON 6 仰角及俯角 | Angle of Elevation and Angle of Depression LESSON 7 方位角 | Bearing LESSON 8 平面圖形的三角比應用 | Application of Trigonometric Ratios in Plane Figures ADD-ON 點解會叫 sin cos tan? | Some Background of Trigonometric Ratios