How to make a decal that is a sector of a circle?

Hi, I want to have a decal on units that show “line of sight”, like in the commandos games. How do I achieve this? Here is a picture from Commandos 2 for reference:

(Talking about the green circle sector that is attached to the tank).

Have you seen how circular progress bars are made?

I think you could make a procedural decal like this.