Answer : The variables used in the equations for centripetal acceleration are, radius and tangential speed.
Explanation :
Centripetal acceleration : It is defined as any object moving in a circular path will have some acceleration vector that pointed towards the center of the circle.
Formula used for centripetal acceleration is,

where,
= centripetal acceleration
r = radius of path
v = velocity or speed of an object or tangential speed
In the equation of centripetal acceleration, the radius and tangential speed are the variables.