Chordae tendinae are threads attaching to the bicupid and tricuspid valves. Bicuspid valve has 2 cusps and it is on the left side. Tricuspid valve is on the right side with 3 cusps in the valve.
2 and 3 are the cusps in the valves. Not the chordae tendinae.Right side is wider opening,so more cusps. Left side is narrow opening so it has 2cusps.