TION 3 reasons for your statements in Questions 3,4 and 5. diagram, O is the centre of the circle ACB. TA and TB are tangents to the circle at A T are joined. BTM-110°. C 1 1/2 B 2 110° 2 1 T A Prove that: 3.1.1 AOBT is a cyclic quadrilateral. 3.1.2 -T Calculate the size of Ĉ