• Angle • Measurement of angles • Relations between radian measure and sexagesimal measure • Trigonometric ratios (functions) of an acute angle • Relations and identities involving trigonometric ratios • Trigonometric ratios of and • Heights and distance • Trigonometric ratios of any angle • Trigonometric ratios of allied angles • Trigonometric ratios of compound angles • Trigonometric ratios of multiple and submultiple angles • Transformation formulae • Graphs of and • Relations between the sides and angles of a triangle • Solution of triangles