Explanation:

To determine the circumference of the circle, we can use the formula related to arc length and central angle:

- Arc Length Formula: \( L = \frac{\theta}{360^\circ} \times C \)

- \( L = 18 \, \text{cm} \) (Length of the arc)

- \( \theta = 28.8^\circ \) (Central angle)

- \( C \) is the circumference we want to find.

- Solving for Circumference:

$$

18 = \frac{28.8}{360} \times C

$$

$$

C = \frac{18 \times 360}{28.8} = 225 \, \text{cm}

$$

- Option Analysis:

- Option 1: 180 cm, incorrect as calculation shows otherwise.

- Option 2: 216 cm, incorrect based on formula.

- Option 3: 225 cm, Correct based on calculation.

- Option 4: 240 cm, incorrect based on calculation.

Therefore, your selected answer is option:3- 225 cm. .