Answer:
3.5 cm
Step-by-step explanation:
Length of an arc is a "part" of the circumference of a circle.
The circumference is the perimeter of the circle. Formula is:

Where
C is circumference
d is diameter
Given diameter is 16, the circumference would be:

Now, the arc is 25 degrees, which is 25/360 th of the circle's circumference [recall, there is 360 degrees in whole circle].
So, we multiply the circumference we got by (25/360) to get our answer:

Minor Arc JH = 3.5 cm