
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
In quadrilateral $ABCD$, if $AD$ is parallel to $BC$ and $AB$ is parallel to $CD$, in order for quadrilateral $ABCD$ to be a rectangle, the additional condition that needs to be satisfied can be _______ $(just fill in one condition that you think is appropriate)$.

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