This is the 6036th most frequent Russian word.
соглашаться
"Соглашаться" means "to agree."
In this sentence, 'согласился' (past tense form of 'соглашаться') means 'agreed' and indicates acceptance or consent to do something.
Я согласился помочь ей с проектом.
I agreed to help her with the project.
Here, 'согласился' means 'agreed with' and is used to express an alignment or concurrence with someone's opinion or idea.
Он согласился с ее аргументом.
He agreed with her argument.
In this instance, 'соглашаться' (present tense) conveys the regular action of finding agreement or mutual understanding among individuals.