Question

prove that every line segment has one and only one midpoint

Answer 1

since line can be divided into 2 equal halves it has only one midpoint

Answer 2

1). suppose C and C' are two mid points of segment AB.

2). Then AC = AB.

3). and AC' = AB.

4). AC = AC' ( things which are equal to the same thing are equal to one another. )

5). This is possible only when C and C' are coincide.

6). Hence every line segment has one and only one midpoint.