From an external point P, a line segment PT is drawn to touch a circle with centre O and radius r at the point T. Answer the following:
(a) Part 1: (i) Draw a neat, labelled diagram for the above situation and state the angle between OT and PT, giving reason.
(b) Part 2: (ii) Explain whether a tangent can be drawn from P if OP=r. Justify your answer.
(c) Part 3: (iii) Give a reason why no tangent can be drawn from P if OP<r.