If both the magnitude and direction of acceleration of a body is constant, does it mean that the path of the body be necessarily be a straight line?

Is radius of gyration of a body a constant quantity?

What is the direction of angular momentum of a body?

Is it possible to accelerate a body if its speed is constant?

What do we mean by saying that the acceleration of body is 3ms^-2 ?

A vector has both magnitude and direction. Does it mean that anything that has magnitude and direction is necessarily a vector ?The rotation of a body can be specified by the direction of the axis of rotation, and the angle of rotation about the axis. Does that make any rotation a vector ?