x =11
Explanation:
Scale factor : A scale factor is a number which multiplies of some quantity.
Given that
≅

SSS rule : If three sides of a triangle are congruent to the sides of another triangle. Then two triangle are congruent .
Since
and
congruent.
Then,

Taking first two ratio

⇔
[ RS = 3 , ST= 5.5, MN= 6 and NO=x]
⇔3x =6×5.5
⇔

⇔x =11