Sorry for asking this again in new ask cause I don't know how to reply my previous question.
To explain my problem more clearly, I attached some images and the part file.
I draw a horizontal line in sketch 1, and in sketch 6 I draw a line which have dimension is 3.
I want this line ( in sketch 6) is perpendicular with plan of sketch 1.
If I choose relation for this line is horizontal (which I think is vertical to sketch 1) , the angle between it and the horizontal in sketch 1 is just 89.80 degree.
I don’t know what is the reason for that different. Cause I have same drawing, in which I choose the relation is horizontal too and the angle is 90 degree