The question is seriously misguided.
A linear inch is the same as an inch. So 30 inches has always been equal to 30 linear inches and never 45 linear inches. So the issue of "still" does not arise.
Metres and linear metres are the same measurement. Therefore, 30 metres is equal to 30 metres.Metres and linear metres are the same measurement. Therefore, 30 metres is equal to 30 metres.
30 inches is equal to the metric measurement of 76.2 centimetres.
30 inches is equal to 2.5 feet because there are 12 inches in a foot.
Feet and linear feet are the same measurement. Therefore, 30 feet is equal to 30 feet.
One mile is equal to 63360 inches. Therefore, 30 inches is equal to 30/63360 = 0.047348 recurring (that is, 0.0473484848..) miles.
Metres and linear metres are the same measurement - the word linear is used to contrast it from square metres or cubic metres. Therefore, 30 metres is equal to 30 linear metres.
30 inches is equal to 2.5 feet. This is because there are 12 inches in a foot, so you can divide 30 by 12 to convert inches to feet.
There are 36 inches in one yard. Therefore, 30 yards is equal to 30 x 36 = 1080 inches.
There are 12 inches in 1 foot so there are 12 x 30 inches, which is 360 inches, in 30 feet.
30 inches = 0.762 metres
No, one's linear and the other's volume
It depends on the context, but for airlines luggage, it would count as 18+28+30 = 76 inches