Answer the following questions related to line segments in a triangle.
(i) Define the midpoint of a line segment.
(ii) Explain, with reasons, the relation between the segment joining the midpoints of two sides of a triangle and the third side.
(iii) A student claims that if a quadrilateral has one pair of opposite sides parallel and equal in length, it must be a parallelogram. Using the idea in part (ii), describe how you could place such a quadrilateral inside a triangle to verify the student’s claim without measuring any angles. Give full reasoning.