23. As shown in the figure, point $O$ is the center of rectangle $A B C D$, and quadrilateral $A O E F$ is a square. $A B=12 \mathrm{~cm}$, $A D=16 \mathrm{~cm}, B D=20 \mathrm{~cm}$, the area of the red part is larger than the blue part by $\_\mathrm{cm}^{2}$.
$52$