Yeah, thats right. All triads are built that way. The root, the third from the root, and the 5th from the root. If you were to do it in numbers it would be starting with 1, skip 2, 3, skip 4, 5. There's your major triad. If you ever seen "formulas", this is what they're doing. Converting the notes into numbers. So if you wanted to add a seventh to a chord, you would just count up to 7, skipping the 6th note. There's your note.