As a past participle of the verb "to view":
* I have viewed the documentary twice. (meaning: I have watched the documentary twice)
* The painting was viewed by millions of people. (meaning: Millions of people looked at the painting)
* The project was viewed as a success. (meaning: People considered the project to be successful)
As an adjective:
* The viewed footage was incredibly disturbing. (meaning: The footage that had been seen was disturbing)
* The artist's work is viewed by critics as groundbreaking. (meaning: The artist's work is considered to be groundbreaking by critics)
* The viewed results showed a significant increase in sales. (meaning: The results that were observed showed a significant increase in sales)
In a different context:
* From a different viewpoint, the situation can be viewed in a more positive light. (meaning: Looking at the situation from a different angle, it can be seen in a more positive way)
* He viewed the world with optimism. (meaning: He saw the world as a positive place)
Remember that the meaning of "viewed" can change depending on the context. Always consider the sentence as a whole to understand the intended meaning.