
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 a circle, the diameter $\overline{FB}$ is parallel to $\overline{DC}$, and $\overline{AB}$ is parallel to $\overline{FD}$. The angles $AFB$ and $ABF$ are in the ratio $3:7$. Determine the degree measure of angle $BCD$.
A) 45
B) 54
C) 63
D) 72
E) 81

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