2024 IMC keystage3-IWYMIC team Question 5

In the diagram, $PQRS$ is a square inside a regular 9-gon, with $P$ a vertex of the 9-gon and $R$ the intersection of the two drawn diagonals. If a side of the 9-gon is 48 cm, find the area of $PQRS$ in $\mathrm{cm}^2$.