6. (10 points) In a large rectangle, four small squares are placed as shown in the figure. If the side length of each small square is 6 cm, then the area of the shaded part in the figure is $\qquad$ square centimeters.



The above text has been translated into English, retaining the original text's line breaks and format.
【Solution】Solution:
$$
\begin{array}{l}
6 \times 6 \times 3.5 \\
=36 \times 3.5 \\
=126 \text { (square centimeters) }
\end{array}
$$

Answer: The area of the shaded part in the figure is 126 square centimeters. Therefore, the answer is: 126.