
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
The base of a pyramid $S A B C D$ is a rectangle $A B C D$, where $A B = a$, $A D = b$; $S C$ is the height of the pyramid, $C S = h$. Find the dihedral angle between the planes $A B S$ and $A D S$.

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