S Chand ICSE Mathematics Class 9 Solution Nineteenth Chapter Trigonometrical Ratios Exercise 19B (O.P. Malhotra, S.K. Gupta, Anubhuti Gangal) Mimi Das September 17, 2019 OP Malhotra, SChand ICSE Math Comments S Chand ICSE Mathematics Class 9 Solution Nineteenth Chapter Trigonometrical Ratios Exercise 19B (O.P. Malhotra, S.K. Gupta, Anubhuti Gangal)