Then I used snap to edge to get them close and snap to vertices to connect them.
QUESTIONS:
I want to do next:
Cut their ending with angle, with easier approach if there is one!?
connect them (join), connect two angles without using snap, because snap distorts one of the tubes if they are not aligned perfectly (and I didn’t find a way to align them perfectly, snap edge only aligns on one edge not four)
What might help is Shear command and Transform orientations set as needed.
Shear could be found and is easier to use on Space menu - 4 finger combination ;); value you set is in radians 3.14/2 = 90deg. You need to be in edit ortho view to use it. If that was z scaled default cube with one edgeloop, select top and edgeloop vertices and use Shear.
To move things around not on xyz global or local axis you set new ones by selecting some edge and defining New Transform orientation (N-panel, down; +sign). This gets into the list where you usually select orientation (delete it where you set it).
While not so convenient, hope, this might help some.
Blender is not a precision modeling tool but there are some things you can do. I’m sure there are more ways to do these but couple of tips:
You can enable face angles from the mesh display (in edit mode). Here I’m shearing in up/down direction (ctrl+alt+shift+s, middle mouse button click) and see the angles. Also, my pivot is set to 3D cursor to keep the other end where it is.
[ATTACH=CONFIG]210078[/ATTACH]
And here I used snapping to snap it together. First moving and snapping two edges together, then rotating and snapping. Pivot is set to active element and I first rotated the object so that it snaps from another direction. You can select mesh parts by hovering over one and pressing L, or alternatively select one element and then ctrl+L to select all linked to that.
[ATTACH=CONFIG]210084[/ATTACH]
Of course, in this example you could just extrude the edge/face that was set to angle and not snap anything.
Precise work make one extra edge somewhere and rotate to degrees you want and make it triangle. Then use Knife and cut through (Z) -option. Your knife will snap to 2 vertices you made from edge.