How can I check the distance between two segments in a part?

In the following image I need to check A & B distances:

Normally Measure tools shows the distance between two items.

But if the two items intersects it shows nothing but a message that reads as :

The selected items intersects.

How can I check the distance between the line and the circle?

A test part is attatched if you need to work on it.

Any kind of help is much appreciated.