Hi,
I want to make a tripod.
How to snap the legs?
best regards.
What does that mean?
How far have you come modelling the tripod?
I will try to be more clearly.
image shows what I want to make.
To which part of the legs do you want to snap to? If it’s the semi-sphere that represents the bottom of the legs, you might be able to snap to it with the Center snap, depending on how these where created. Make sure you locate your mouse cursor close to the edge of that sphere. Rhino detects center snaps if it’s at the perimeter of the circle only.
This is what I got from the lines.
I wonder how to snape “tube” on “sphere” where i want.
My english is bad.
I hope that you understand what i want to say 
Hi Salex - OrientOnSrf may be what you are looking for - give that a try. The interface can be confusing - make sure to select the cylinder in a view where it is vertical to the construction plane.
Or possibly, Line > Normal and then Pipe the line or Orient a cylinder to the line.
-Pascal