
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 trapezoid  $ABCD$ , the sides  $AD$  and  $BC$  are parallel, and  $AB = BC = BD$ . The height  $BK$  intersects the diagonal  $AC$  at  $M$ . Find  $\angle CDM$ .

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