
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
 $\triangle ABC$  is an acute angled triangle. Perpendiculars drawn from its vertices on the opposite sides are  $AD$ ,  $BE$  and  $CF$ . The line parallel to  $ DF$  through  $E$  meets  $BC$  at  $Y$  and  $BA$  at  $X$ .  $DF$  and  $CA$  meet at  $Z$ . Circumcircle of  $XYZ$  meets  $AC$  at  $S$ . Given,  $\angle B=33 ^\circ.$  find the angle  $\angle FSD $  with proof. 

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