If A, B and C are interior angles of a triangle ABC, then show that sin(2/B+C) = cos 2/A. B and C are interior angles of a triangle ABC If A then show that sin(2/B+C) = cos 2/A. October 5, 2020 Category: Chapter 8 - Introduction to Trigonometry , Maths , NCERT Class 10 , Facebook Messenger WhatsApp Share this:TwitterFacebook Related