A circle is centered at the origin and has radius of 4. A particle starts at point (4,0) and travels clockwise on the circle, making one complete revolution

What's the question???

The equation of the circle will be 

$x^2+y^2=16$

The particle will travel   

$2\pi*4=8\pi\;units$

Ok now I have run out of ideas.....   Err what is the question  ?????