Hi, you are probably confusing the angular dimension tool with a click, or clicks.
Please try placing the dimension in either one of this ways:
1. select a first edge (click1)
select a second edge (click 2)
place the dimension to where you wish the dim to appear (click3) or
2. select the first point of vector 1 to determine the beginning of line/edge 1 (click1)
select the second point of vector 1 to determine the end of line/edge 1 (click2)
then select the first point of vector 2 to determine the beginning of line/edge 2 (click3)
and select the second point of vector 2 to determine the end of line/edge 2 (click4)
place the dimension to where you wish the dim to appear (click5)
let us know if your trouble still persists! Tx, k