Measurement Of Angles On Holes

Introduction
By creating angles for holes it's not possible to use vertical or horizontal center lines (false/true) from the properties of the view. Helping lines and/or helping points are necessary for creating.

Proceeding:
1.Setting center lines on holes:

There are some possibilities to create a center line for holes. At first the lines or points on the hole must be selected as shown below. Behind them the tool  or   from the tool bar is creating the center line.