
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 rectangle has a length that is three times its width, and the diagonal is $d$. Find the area of this rectangle in terms of $d$.
**A**. $\frac{d^2}{10}$  
**B**. $\frac{2d^2}{10}$  
**C**. $\frac{3d^2}{10}$  
**D**. $\frac{4d^2}{10}$  
**E**. $\frac{5d^2}{10}$

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