
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 an isosceles triangle with sides $a, a, b$, where $b$ is the base, the product of the two congruent sides' lengths is equal to three times the product of the base and the triangle's height to the base. If the vertex angle is obtuse, determine its measure in degrees.
A) 100 degrees
B) 120 degrees
C) 130 degrees
D) 141 degrees
E) 150 degrees

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