Question

why uniform circular motion is said to be accelerated

Answer 1

because the direction is not same so is the velocity and accelaration is the rate of change of velocity

Answer 2

uniform circular motionis said to be accelerated.
any motion would be called accelerated if its velocity changes with respect to time.
and in uniform circular motion the velocity is getting changed every single time because its a circular motion and the direction is getting changed with the motion.so it is accelerated motion.