Answer:
"perpendicular" or at a "right angle"
Explanation:
an example of a transverse wave is the wave created by a string being moved up and down
the wave travels to the right (or left) through the string, while a particle of the string is moved up and down (in other words: if you put a mark on one part of the string, the mark would only move up and down)
since moving right is perpendicular to moving up/down, the disturbance is perpendicular to the wave motion
