10. The area of square $A B C D$ is 9 square centimeters, and the area of square $E F G H$ is 64 square centimeters. As shown in the figure, side $B C$ lies on $E H$. Given that the area of triangle $A C G$ is 6.75 square centimeters, then the area of triangle $A B E$ is square centimeters.
$2.25$