Rotation as a vector
Now this message 6761 from Zapboy displays even worse understanding (than originally) of vectors.
A first position can defined as vector ~r1, with reference to some origin; a second position can be defined as vector ~r2; the linear displacement from position one to two is a third vector ~r3 = ~r2 - ~r1.
If all these vectors were co-linear, then the magnitude of the displacement r3 can be obtained by arithmetic (scalar) subtraction, but the direction of r3 does not disappear, it is still a VECTOR, not a SCALAR as Zapboy so egregiously machinates.
Yes the original question DID state that (linear) displacement is a vector, and that is correct.
The original question went on to ask if (angular) displacement is also a vector. IT IS NOT !!
Zapboy contributes no increase to the body of human knowledge by his constant cavilling with words, rather than pursuing exact understanding.