An example of a trio is two boys and a girl.
An example of a trio is a band with a guitarist, drummer and bassist.
The trio was out of camera range a few steps later.
Fred joined the trio and nodded in agreement.
"Don't get us lost," Cynthia cautioned as the trio began the climb downward, away from the mine.
When the trio came back from their walk, the men said their goodbyes and left.
The others followed and the trio went back inside where Dean began building a fire.