Dear skamal

You see you need to understand the difference between circumference and area visually first.

if you draw a circle on paper then:-

the boundary of circle called circumference . it formula is 2*pie*radius

the space covered inside the closed boundary and also the space covered by the drawing of boundary(how so ever small it is) is called area..

Now you need to draw sign.

Unless stated otherwise, you can safely assume that you draw fully filled circle and not a empty circle.

Hope it helps

Kudos please if you like it.