The Dimension arms and lines not the same length

[jbento22]

[jbento22]

The lines are not aligned and I really need to understand why and how to fix it. I used the AEC Dimensions. 

[imadHabash]

Hi,

You can control the length of those extension lines from Dimension style manager >> Modify >> Lines tab >> Tick the option " Fixed length extension lines " and you can put a value. >> Click <<