
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Four coplanar squares with sides of lengths three, five, and seven units, respectively, are arranged side-by-side such that one side of each square lies along line $CD$. A segment connects the bottom-left corner of the smallest square to the upper right corner of the largest square. Determine the area of the resulting trapezoid shaded in the diagram. 
[Visual representation is similar to the original with updated side lengths and labels.]

Present the answer in LaTex format: \boxed{Your answer}
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