how to draw Two circle ? and how to have collision ? :(

Answer 1

You set javascript and java tags to your question, but both are totally different: for wich of this do you need help ?

In the other hand, if by "how to have collision" you think of collision detection, I suggest you to look at the games framework and 3d/2d engines ( on all langage, without a third party framework, you've no choice but to write it from scratch )...

Answer 2

Well, the second part of my previous answer is still relevant ^^

Make an algorithm for collision detection isn't difficult, especially if you treat only circles: in this case, coding your own remains possible :)
You have only to know center positions and radius ( r1 and r2 ), and to compare the distance d between centers of each two circles ( or iterate over all pairs of circles combinaisons ):

IF d > r1+r2
THEN the two circles do not touch,

ELSE IF d < r1+r2
THEN the two circles do overlap,

ELSE d == r1+r2
THEN the two circles do touch, but without overlap...

And about how to draw circles, I let you search ( or wait for another answer ), because I don't have myself the response immediatly, without some researches ;)

______________
Reminder: the formula wich get the distance between two dots ( x1,y1 and x2,y2 ) is ( SQR --> square root ):

d = SQR( ( x1-x2 )² + (y1-y2)² )

[ EDIT ]
Think to take in account the thickness of your drawing line in addition of the radius, if it make sense...

Answer 3

In javaa