12. Two squares $A B C D$ and $B E F G$ with side lengths of $8 \mathrm{~cm}$ and $6 \mathrm{~cm}$ respectively are placed side by side as shown in the figure. Connecting $D E$ intersects $B G$ at $P$. What is the area of the shaded region $A P E G$ in the figure?
【Key Points】Geometry, Equal Area Transformation
【Difficulty】ふうふ
【Answer】 18
【Analysis】Move $\triangle A P G$ to $\triangle D P G$ (as shown in the middle figure below), connect $D B, D B$ is parallel to $G E$. $\triangle D G E$ is equal in area to $\triangle B G E$ (as shown in the right figure below). $6 \times 6 \div 2=18$.