My cabin bag linear length is 125 cm. Tha bag can use as cabin bag? Please help me to find solution for cabin bag. Thank you.
Carry-on (cabin) luggage is almost always restricted in terms of absolute limits on length, width, and height rather than a single linear size. See for example, for Lufthansa:
Here’s a metric version that compares several airlines:
If you’re flying business or first class international, sometimes the cabin attendants will let you store longer items in the coat closet. Economy travelers can sometimes get crutches and canes stored there too.
Otherwise, you’ll likely be asked to gate check your bag if it exceeds the cabin luggage dimensional restrictions (or if the cabin is full).