Question

Formula to find the midpoint of a line segment

Answer 1

Return length(line_segment)/2.0

Answer 2

(x1,y1) and (x2,y2) are the two points of the line segment
and the formula is : sqr rt((x2-x1)square-(y2-y1)square)

Answer 3

That's not it, that's the formula for a generic line in the Oxy.
The right formula is:

xm = (x1+x2)/2
ym = (y1+y2)/2

the point will be (xm,ym)

Answer 4

sry.. its (x1+x2)/2 +(y1+y2)/2