Question

if a bicycle wheel 18 spokes then the angle between apair of adjacent spokes is

Answer 1

the angle between a pair of adjacent spokes=360/18
                                                                      =20

Answer 2

A bicycle wheel is of a full circle.
It is divided into 18 parts.
Thus the complete central angle of the circle is 360°.
So the angle between a pair of agent spokes is 360/18 = 20°