Given :
As it is not given whether RST and NPQ are collinear points or vertices of Triangle.
Whatever , if these two shapes are congruent , then their corresponding parts whether side length or Part or whole of segment will be congruent with each other.
RT = N Q [Corresponding part of congruent shapes]
→7 x -5 = 5 x + 11
Taking variable on one side and constant on another side
7 x - 5 x = 11 + 5
2 x = 16
Dividing both sides by 2, we get
x=8
RT = 7 × 8 -5= 56 -5 =51 Units
N Q= 5 × 8 + 11= 40 + 11= 51 Units