Answer:
They all equal
because they all give 
Step-by-step explanation:
They all equal
because they all give 
Done by writing three equations with one random number and the desired result,
, returning the answers above.
1) -12 meters
2) 28 meters
3) 40 meters apart
Having two opposite faces plane and parallel a plane-parallel sheet of glass.
Or ?? ⬇️
In geometry, parallel lines are lines in a plane which do not meet; that is, two straight lines in a plane that do not intersect at any point are said to be parallel. Colloquially, curves that do not touch each other or intersect and keep a fixed minimum distance are said to be parallel.