When I add edge loop to this, angle is already broken. How do you make 1 and 2 edge loops parallel each other?
2 Answers
Whether or not you have just created it, if you want to make an edge-loop parallel to an adjacent one, slide the loop with GG. Now hitting E will make the loop parallel to one side or the other. Hitting F will flip which side. Hitting E again will revert to the default behaviour: interpolating between its original orientation, and whichever edge you are sliding towards.
Assuming you used CTRL-R Loop Cut
In edit mode
After loop cut is finished. Scale along an axis with number 0. Hopefully X or Y or Z will work.
sx0
sy0
sz0
or use
[Knife Cut] kwith cut through ON z
the keystrokes are also indicated in the 3D View
Knife cut image above. Unfortunately the screen capture did NOT capture the little knife cursor. The lower left shows the Knife Topology tool panel.
youtube has video tutorials on knife cut which will save you time.
BSE can be searched for Knife Cut.