Choose the Angular Coordinate Dimension command 
.
Click an element that you want to be the group center element (A).
Click to place the common origin (B).
Click an element that you want to measure (C).
Click to place the dimension (D).
Note:
Angular coordinate dimensions should be applied to fully constrained profiles. If an angular coordinate dimension behaves unpredictably (conflict between the displayed dimension and the command bar, for example), make sure the profile is fully constrained.
Tip:
To use a different origin element for additional dimensions, click the right mouse button to start over.
You can control the direction in which the angular coordinate dimension is measured with the Counterclockwise button on the command bar.
You can remove all the jogs on an existing angular coordinate dimension using the Jog button on the Dimension command bar.
You can add jogs to angular coordinate dimensions while placing them by holding the Alt key.