Answer-
[tex]\boxed{\boxed{QR=12}}[/tex]
Solution-
Triangle Midpoint Theorem-
The line segment connecting the midpoints of two sides of a triangle is parallel to the third side and is congruent to one half of the third side.
As given in the question,
QV = SV, so V is the mid point of QS,
SU = RU, so R is the mid point of RS.
Hence, UV is the line joining the midpoints of QS and RS.
Applying Triangle Midpoint Theorem,
[tex]\Rightarrow UV=\dfrac{1}{2}QR[/tex]
[tex]\Rightarrow QR=2UV[/tex]
[tex]\Rightarrow QR=2\times 6[/tex]
[tex]\Rightarrow QR=12[/tex]
Therefore, the side length of QR is 12 units.
