part i)
tangents from an external point are equal in length, answer follows very easily
part ii)
note that K, L, M are 3 points on the circle. the triangles KBL & LCM are isosceles, which means the angle bisectors are perpendicular bisectors of the base lines KL & LM. from the circle property that perpendicular bisectors of chords pass through the center of the circle (not sure if i need to prove this), it follows that the point of intersection X is the center of the circle.
part iii)
not too sure how to approach this one