They were surprised at the news Iwas pleased with the gift.

We are satisfied with the result.

The doctor is known to everybody.

Are above sentences passive voice or be + adjectival (past participle working as adjective)?

How can I know whether past participle is used in passive voice or as adjective?

Thank you.

All are participles as adjectives.

The formation is the same for passive voice and past participles used as adjectives, but passive voice has (or suggests) an actor and a recipient of the action.

The car was destroyed in the collision [probably by another car].
The jar was shattered by the fall from the counter top [the fall shattered te jar].

In some sentences, it’s hard to tell.

John was embarrassed. Was is a state of embarrassment or did someone embarrass him?