
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
A plane flying westward at a constant speed of \(390 \mathrm{~km/} \) at a constant altitude observes an object to the south at a depression angle of \(\alpha = 34^\circ 28' \). After 1 minute, viewing the same stationary object, the depression angle changes to \(\beta = 23^\circ 41' \). What is the altitude at which the plane is flying? (Depression angle: the angle between the line of sight and the horizontal plane.)

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