1. The problem asks to identify which two angles are vertically opposite angles among the angles a, b, c, d, e, f arranged around a point. 2. Vertically opposite angles are pairs of angles formed when two lines intersect. They are opposite each other and are always equal. 3. Since the angles are arranged around a single point, pairs of vertically opposite angles are those that are directly across from each other. 4. From the description, the pairs are: - a and d - b and e - c and f 5. Therefore, the two angles that are vertically opposite are any of these pairs, for example, angles a and d. Final answer: angles a and d are vertically opposite angles.