Can someone please explain this to me? this wasnt even in the text book.

"Because geometric figures consist of sets of points, we can apply set operations to obtain the union (U symbol) or the intersection (Upside down U symbol) of such figures. the union of two geometric figures is the set of points that belong to either of the figures or to both figures. The intersection of two geometric figures is the set of points common to both figures. Use the line shown to find each set of points."​

Can someone please explain this to me this wasnt even in the text bookBecause geometric figures consist of sets of points we can apply set operations to obtain class=