
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
Find the number of units in the length of diagonal $DA$ of the regular octagon shown. Express your answer in simplest radical form.
```asy
size(120);
draw((1,0)--(2.414,0)--(3.414,1)--(3.414,2.414)--(2.414,3.414)--(1,3.414)--(0,2.414)--(0,1)--cycle);
draw((1,0)--(1,3.414));
label("8",(2.914,2.207),NE);
label("$A$",(1,0),SW);
label("$D$",(1,3.414),NW);
```

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