Circumference (C) = 2 π r
122 = 2 π r
61/π = r
Answer to part (b): radius is 61/π ≈ 19.4
Diameter (d) = 2 r
d = 2 (61/π)
d = 122/π
Answer to part (a): diameter is 122/π ≈ 38.8
arc length (s) = r · Ф
THETA MUST BE IN RADIANS!
use the unit circle (or use the proportion π/180°) to discover that 30° = π/6
s = (61/π)·(π/6)
= 61/6
Answer to part (c):arc length is 61/6