
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
Let $ABC$ be a triangle and $k$ be a positive number such that altitudes $AD$, $BE$, and $CF$ are extended past $A$, $B$, and $C$ to points $A'$, $B'$, and $C'$ respectively, where $AA' = kBC$, $BB' = kAC$, and $CC' = kAB$. Suppose further that $A''$ is a point such that the line segment $AA''$ is a rotation of line segment $AA'$ by an angle of $60^\circ$ towards the inside of the original triangle. If triangle $A''B'C'$ is equilateral, find the value of $k$.

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