Answer:
The question is asking for the perimeter. There are three ways to answer this depending on the assumptions though so I'll let you choose.
Assumptions are basically the different scenarios
1st scenario being the trim covers the carpet and the tile, they'd need 48m of trim (12+12+4+8+8+4)
2nd scenario in which the trim covers the carpet but not the tiled area, they'd need 44m of trim (12+12+4+8)
3rd scenario where the trim only covers the the tiled area, 4m of trim
(just 4 since the tile only touches 4m of the wall)
Hope this helps!
Explanation:
trim is just the perimeter since it covers the base of the wall