Acceleration in circular motion

The acceleration in circular motion is centripetal, i.e. directed toward the center of the trajectory.
Move either point A or B such that they are close to each other. and are the velocities of the point, respectively, in A and B. is equal to , but is drawn such that it starts from A, so we can compute graphically the difference . is always perpendicular to the base of an isosceles triangle formed by , and . The height of such a triangle is parallel to the displacement x(B)-x(A). The vector a is compute as : when goes to zero, the time interval dt goes to zero, too, being .When A and B coincide, the acceleration, whose length is constant, points toward the center of the trajectory.