I have read about Rotatory Motion it says
"It is that motion in hwich body, which is not a point mass body is moving such that all its constituent particles move simultaneously along concentric circles, whose centres lie on a line, called axis of rotation and shift through equal angle in a given time".
My question..
Q1. what is the meaning of line "whose centres lie on a line, called axis of rotation and shift through equal angle in a given time". Explain it briefly and clearly. If possible with exampele.