Find the missing segment in the attached image

49 unit.

Step-by-step explanation:

concept used: basic proportionality theorem,

theorem states that, if a line is drawn parallel to one side of the triangle and intersect the other two sides then the two sides are divided in the same ratio.  

Example:

let there be a triangle ABC

if DE is drawn parallel to BC such that D is a point on line AB and E is other point on AC, then

AD/DB = AE/EC (basic proportionality theorem)

Similarly in this problem ,

one side has length of 60 units,

The parallel line divides it at point such that one of the segment of this side is of 35 units.

Then other segment of same side = 60-35 = 25

now using basic proportionality theorem

?/35 = 35/25

=> ?/35 = 7/5

=> ? = 7/5 * 35 = 49

Thus, length of missing side segment is 49 unit.