Please help me i don’t know if I’m right

   your choice is correct

Step-by-step explanation:

The magnitude of the difference between the target amount and the actual amount will be no greater than the allowed error.

  |x -34| ≤ 0.25

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.