Math Chapter Wise Trigonometrical Identities And Circular Function English MCQ PGT 2010 Q.In a triangle ABC, 1 2acsin 2 (A–B+C) is equal to Aa2 +b2 –c2 Bc2 +a2 –b2 Cb2 –c2 –a2 Dc2 –a2 –b2 Show answer Correct answer: c2 +a2 –b2