
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
A rectangular prism has dimensions of 12 inches, 16 inches, and 21 inches. Calculate the length of the diagonal connecting opposite corners of the prism and find the total surface area of the prism. Express the diagonal's length in simplest radical form.

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