"straight" lines showing as crooked...why?

[kizaerf]

Both of these lines are shown as being 180 degrees (i.e. horizontal) but clearly they aren't. How do I fix this?

 

I tried fixing the UCS to be 'world'

[ROBP]

Both of these lines are shown as being 180 degrees (i.e. horizontal) but clearly they aren't. How do I fix this?

 

I tried fixing the UCS to be 'world'

 

Post dwg so we can examine it, could be that both perpendicular lines you are trying to join are not equal seen it so often.

[ROBP]

if line is straight it could be that all the other ones are not starting at the same point

construction lines will tell

[rkent]

Check the Y coordinates, they don't match on the lower image. You need to start the units command and change the precision to see the actual angle.

[nukecad]

As rkent says that second one has different ordinates on the Y value so is not horizontal.

You can also see this by the 'delta Y' reading.

 

Your angle readout is only showing whole degrees so this slight difference does not show there.

 

Use AUPREC to change this to show partial degrees rather than just whole degrees and you will see the difference there as well.

[eldon]

If you have never altered the Angle unit precision, it defaults to 0.

 

Therefore the angle can be plus or minus half a degree before the angle shows any different. As you have noticed, you can see any slight deviation from the x or y axis, but this deviation is smaller than half a degree, so the angle still shows as 0, 90, 180 or 270.