I believe this question uses Angular Diameter to determine the answer but I'm not sure how to use it.
Question: If a widget is 10 meters wide and it is positioned 1,000 meters from the observer how wide will it appear?
Alternate Equation: At what distance will a widget that measures 10 meters wide appear to be 5 meters wide? (Maybe the alt question helps the first question become clearer)
Using this online calculator I inputted 10 meters for Linear Size and 1000 meters for Distance to Object. It returned an Angular Diameter of 0.572953020554149. But how does this help me determine the apparent size of an object at a given distance? Or alternately am I using the wrong formula?
Backstory: I can find many references to Angular Diameter on both Google and this forum. But I can't find one that explains how to use this simple concept to determine on object's apparent size.