と考(かんが)えられているIs considered, Is thought of as

In its citation usage, the case marking particleと is often used with verbs in the passive form. Two of these regularly occurring verbs are 考(かんが)えられている 'to be considered', and 思(おも)われている 'to be thought'.

This grammar point is used after a phrase, and translates as 'it is considered that (A)', or 'it is thought that (A)'. It is generally used to highlight a commonly held opinion that most people agree on (not your personal opinion).

The primary reason that these constructions are used in their displacement (passive) form, is to show that the thought itself is not something that is related to the speaker's own opinions.

However, people will often use this form as a way to strengthen their own opinions, in a similar way to how English speakers would say 'everyone knows that (A)'.