Respuesta :

jonahdanner
radius (r)= 20= 20central angle (θ)= 45degree = 0.78539816339745radian 
 If that doesn't make sense your answer is B. 15.7
 Hope this helps!
apologiabiology
that is circumfereince times degrees/360
circumfrence=2pir=2pi20=40pi in
degrees=45,
so

sectorlength=40pi times 45/360=1/8 times 40pi=5pi or about 15.707


B is answer