Answer:
Ф=144
Ф =s/r ( Ф is the central angle,s is the arc length, r is the radius)
find r:
radius =circumference/2π=1/2π=0.16
Ф=(2/5) /(1/2π)=4π/5=144 degree (π=180)
Ф in degrees: 144 degrees
