A889678, T137121, and M033616 all match each other on an 11.1 cM segment on chromosome 9.
To figure this out, you can use GEDmatch's free Multiple Kit Analysis and their One-to-one compare. Multiple Kit Analysis shows that on chromosome 9 A889678 matches T137121 from 112209452 - 135951119 (34.685 cM), and A889678 matches M033616 from 99962228 - 120368347 (25.774 cM). To discover the number of centimorgans for the overlap between T137121 and M033616 you can then use the One-to-one compare which shows a 11.1 cM shared between them. In other words the shared segment from all three on chromosome 9 is 11.1 cM.