Answer:
π
Step-by-step explanation:
a circle contains 360° in total, so given it's circumference (lets say C),
the length of an arc with angle α is (α/360)*C
for our exanple, the length of arc AB, will be (20/360)*C
as C is given to be 18π cm, we can calculate:
Length(AB) = (20/360)*18π = π
