How to dimension the arc angle in ProE Sketcher

How to add an angular dimension for an arc in ProE Sketcher Mode.

I have seen people creating radial construction lines at the beginning and at the end to insert the angular dimension. But thats not necessary. There is an easier way.

1) Click on one end point. (Left Button)
2) Click on the other end point. (Left Button)
3) Click on the Arc. (Left Button)
4) Place the dimension. (click with middle mutton)

See the result below.

Next time you could save couple of center-lines and get more clean sketch.