Prove that opposite sides of a quadrilateral circumscribing a circle subtend supplementary angles at the centre of the circle. Prove that opposite sides of a quadrilateral circumscribing a circle subtend supplementary angles at the centre of the circle. October 6, 2020 Category: Chapter 10 - Circles , Maths , NCERT Class 10 , Facebook Messenger WhatsApp Share this:TwitterFacebook Related