(i) Since angle AOC and angle BOC are both 2.3 radians, angle AOB is calculated as:

\(\angle AOB = 2\pi - 2 \times 2.3 = 1.683 \text{ radians (correct to 4 significant figures)}\)

(ii) The area of the shaded region ACBP can be found by calculating the area of the sector AOB and subtracting the areas of triangles AOC and BOC.

The area of triangle AOC is given by:

\(\frac{1}{2} \times 3^2 \times \sin(2.3)\)

The area of triangle BOC is the same as triangle AOC.

The area of sector AOB is:

\(\frac{1}{2} \times 3^2 \times 1.683\)

Thus, the area of the shaded region ACBP is:

\(2 \times \frac{1}{2} \times 3^2 \times \sin(2.3) + \frac{1}{2} \times 3^2 \times 1.683 = 14.3 \text{ (correct to 3 significant figures)}\)