Size is usually how large. Quantity is how many.
size
A vector represents quantity that only has size, or magnitude, without any specific direction.
A scalar quantity is a physical measure of size--or extent--,while, on the other hand, a vector quantity is a physical measurement of size--or extent--AND direction. A shape has size--or extent--but does not have direction; and I would, therefore, classify it as having a scalar quantity
A scalar quantity. Scalars are represented by a magnitude and do not have a direction associated with them. Examples include speed, distance, and mass.
A vector quantity
size
A vector quantity has both size (magnitude) and direction involved but a scalar quantity only has size involved and not direction.
The absolute value IS the size of a quantity.
A vector represents quantity that only has size, or magnitude, without any specific direction.
To measure, or measuring is the use of units to find a size of quantity
A vector quantity not only has a size, it also has a direction. Velocity is a vector quantity. "30 mph north" and "30 mph east" are different velocities. "Speed" is a part of velocity ... its size alone, without its direction, so speed is not a vector quantity.
Quantity
a vector
... then what is the question?
A reference quantity.
A scalar quantity is a physical measure of size--or extent--,while, on the other hand, a vector quantity is a physical measurement of size--or extent--AND direction. A shape has size--or extent--but does not have direction; and I would, therefore, classify it as having a scalar quantity
it depends on size and quantity