The scale factor is:

So you divide the corresponding lengths and the ratio you get is the scale factor. Hope it helps!
Answer:
18.174x
Step-by-step explanation:
Steps to solve:
25 = x + 19
~Subtract 19 to both sides
6 = x
Best of Luck!
To find arc length, start by dividing the arc's central angle in degrees by 360. Then, multiply that number by the radius of the circle. Finally, multiply that number by 2 × pi to find the arc length.