I'm really not having a good night 
With reference to the attached, artistically modified, image - could someone please help me with the following:
1) all I want to do is change the 3740 dimension. I've tried clicking on it and all I get is the fabled dimension text dialog which allows me to fudge the dimension and not change it. I've highlighted the horizontal section of the wall and tried changing the dimension, again with no luck. It is not locked so I don't see why I cannot change it??????
2) how do I dimension to the center of the wall? All I want it to ensure the two angled sections are equal in length both sides of the center of the horizontal wall.
3) how do I ensure points A & B are aligned horizontally?
Thanks for your help.
