Please solve question number 4 , it's urgent please solve it

Please solve question number 4 , it's urgent please solve it e3G.Il' cn 10:48AM 4. If O be the centre of the circle, find the value of iiih 'iii/2 in each of the following figures. o 5. Prove that equal chords of a circle subtend equal angle at the centre. 6. The line drawn through the centre of a circle to bis cta chord is perpendicular to the chord. Prove it. 7. Prove that equal chords of a circle (or congruent ci cles are equidistant from the centre (or centres). 8. In the figure, OD is perpendicular to the chord AB fa circle with centre O. If BC is a diameter, show that AC II and AC = 20D. o TOP