concaveshaped

Concave-shaped describes an object or surface that curves inward, away from a central point. This is in contrast to a convex shape, which curves outward. Think of the inside of a bowl; that is a concave surface. Similarly, a crescent moon appears concave from certain viewpoints. In mathematics, a concave function is one where the line segment connecting any two points on the function's graph lies below or on the graph itself. This property is important in optimization problems, where finding the minimum of a concave function is equivalent to finding the maximum of a related convex function. The term can also be applied to geometric figures. For instance, a concave polygon is one that contains at least one interior angle greater than 180 degrees, meaning at least one vertex points inward. This results in a shape where a line segment connecting two points within the polygon might pass outside the polygon's boundary. Examples include a star shape or a boomerang. In everyday language, "concave" often implies a hollow or indented quality.