
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 $\overrightarrow {i}$ and $\overrightarrow {j}$ be unit vectors in a plane Cartesian coordinate system (with the origin O) that are in the same direction as the positive x-axis and y-axis, respectively. Given $\overrightarrow {OA}=-2 \overrightarrow {i}+ \overrightarrow {j}$ and $\overrightarrow {OB}=4 \overrightarrow {i}+3 \overrightarrow {j}$, the area of $\triangle OAB$ is \_\_\_\_\_\_.

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