Hello Niki,
The formula to find the arc length is: arc_length = radius * (central angle in RADIANS)
So all you have to do is grab your calculator and do 25 * 2π/7.
I did it on mine and I get 22.4399475256....
I'll let you round to the nearest hundredth, aka "only keep 2 digits AFTER the decimal"
You got this.