6、The area of the parallelogram is 60 square centimeters, $\mathrm{E}$ is the midpoint of $\mathrm{CD}$. The area of the shaded part is $\qquad$ square centimeters.
【Analysis】 $S_{\triangle A B E}=\frac{1}{2} S_{A B C D}=30, S_{\triangle A O B}=\frac{1}{4} S_{A B C D}=15, S_{\text { shaded }}=S_{\triangle A B E}-S_{\triangle A O B}=15$ square centimeters.