Angle in radians = Angle in degrees × \(\frac{\pi}{180}\)
θ = 1/r Where θ is central angle, L = length of arc, r = radius
Now,
θ = 1/r and r = 0.5 x diameter
= 16.5/30 radius
θ in degrees
= 
θ in minutes = 0.5 x 60 = 30’
Therefore angle subtended at the center is 31° 30’
