Table Tennis and Badminton are Olympic sports. Racquetball, however, is not.
Racquetball is not an Olympic sport.
Court configuration aside for all four sports... For strokes and general play, squash and racquetball are most similar. For court strategy and the value of physical conditioning, badminton and squash are most similar.
for APEX... volleyball
Basketball, racquetball, tennis, volleyball.
A racket is a sports implement consisting of a handled frame with an open hoop across which a network of cord is stretched tightly. It is used for striking a ball in such games as squash, tennis, racquetball, and badminton
Tennis, Table Tennis, and volleyball
Some similar sports to badminton are tennis and pickleball.
The two sports were tennis and handball.