In the 10th grade E textbook of VN
(*) Although it is a long day for us, we are contented with what we do.
and in some exercises, contented with is also used.
According to the OALD
content (adj) [not before noun] content (with something)
content - Definition and pronunciation | Oxford Advanced Learners Dictionary at OxfordLearnersDictionaries.com
contented (adj) [usually before noun]
contented - Definition and pronunciation | Oxford Advanced Learners Dictionary at OxfordLearnersDictionaries.com
(There is no "contented with sth")
I am wondering whether (*) is all right.