Final answer:
To find the area of a sector of a circle, use the formula (angle/360) * pi * r^2. In this case, the angle is 120 degrees and the radius is 18 cm, resulting in an area of approximately 339.3 cm².
Step-by-step explanation:
To find the area of a sector of a circle, you can use the formula:
Area of sector = (angle/360) * pi * r^2
In this case, the angle at the center of the circle is 120 degrees and the radius is 18 cm. Plugging in these values, we have:
Area of sector = (120/360) * pi * 18^2 = 2/6 * pi * 324 = 108 * pi ≈ 339.3 cm²
Therefore, the correct answer is B. 339.3 cm².