Pedagogy of Mathematics (Part II) - Trigonometry, Trigonometry, Maths, IX std Maths, Samacheerkalvi maths, II year B.Ed., Pedagogy, Mathematics, Trigonometric Ratios of Some Special Angles, Trigonometric ratios of 45°, Trigonometric ratios of 30° and 60°,Trigonometric ratios of 0° and 90°,