On vector and scalar Why are velocity and acceleration vectors? They don't use parallelogram rule when they are calculated, And they can also be compared in size How to distinguish between vector and scalar?

On vector and scalar Why are velocity and acceleration vectors? They don't use parallelogram rule when they are calculated, And they can also be compared in size How to distinguish between vector and scalar?

① Both velocity and acceleration are vectors, which are called vectors in mathematics. These two physical quantities have size and direction. For example, a and B objects are moving at a speed of 5m / s, one to the East and one to the West. You can only say that their speed is the same, not the same speed. The same refers to the same size and direction