the direction is always perpendicular to the direction of motion, and the direction changes all the time and points to the center of the circle. regardless of whether the magnitude of the acceleration a changes, the direction of a changes all the time, so the circular motion must be a variable acceleration motion. it can be understood as the component of the acceleration of an object in circular motion in the direction toward the center of the circle.

centripetal acceleration calculation

centripetal acceleration: a=v² / r

r = radius

v = speed