2𝛑 r = circumference

We go around 255degrees out of 360 degrees, so:

(255/360) * 2𝛑 r = 52m

r = 52m (360/250) /(2𝛑)

r = 52m (360/250) /(2*3.14)

r = 11.923566878980892 m

Now round to 2 sigfigs since 52m has 2 sigfigs

12m is the correct answer

S = r Θ ===> 52 = r [255/180 ]π ....solve