The question asks for the measure of an interior angle of a regular polygon with 10 sides.
For any regular polygon with $n$ sides, the formula to calculate the measure of each interior angle is:
$ \text{Interior Angle} = \frac{(n-2) \times 180^\circ}{n} $
In this case, the polygon has 10 sides, so $n = 10$. Plugging this value into the formula:
$ \text{Interior Angle} = \frac{(10-2) \times 180^\circ}{10} $
$ \text{Interior Angle} = \frac{8 \times 180^\circ}{10} $
$ \text{Interior Angle} = \frac{1440^\circ}{10} $
$ \text{Interior Angle} = 144^\circ $
Therefore, the interior angle between the sides of a regular polygon with 10 sides is 144 degrees.
The city of Atlantis was crafted by the God of the seas, Poseidon. It was made of alternating concentric circular rings of land (shaded) and water (not shaded) as represented in the figure (not to scale). The radius of Inner Island was 2.5 stades (a unit of length used in ancient Greece). The water surrounding Inner Island was one stade wide (length AB). This was surrounded by two pairs of alternating rings of land and water. The first pair of land and water was two stades wide each (lengths BC and CD), and the outer pair is three stades wide each (lengths DE and EF).
The ratio of the surface area of the land to that of the water in the city of Atlantis is _________ (round off to two decimal places).

In the given figure, $P, Q$, and $R$ are three points on a circle of radius 10 cm with $O$ as its center, $\overline{PQ} = \overline{RQ}$, and $\angle PQR = 45^\circ$. The figure is representative.
The area of the shaded region $PQRO$ is ______________ cm$^2$.
