Answer:
8 units
Explanation:
Note that 120 degrees represents 1/3 of 360 degrees. The arc described here is thus 1/3 of the circumference of this circle.
Find this circumference and then multiply that result by 1/3:
The formula for the circumference of a circle with radius r is C = 2πr. Here,
(1/3)*(2)(π)(4 units) = 8.38 units, or (to the nearest integer) approx. 8 units.