
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
To calculate the area of an isosceles triangle, the Egyptians took half the product of the base and one of the equal sides. Calculate the percentage error in the following example:

Base 4, equal side 10.

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