What do concave and convex mean?
Official EPGY Definitions:
Concave: A figure is concave if at least one line segment connecting
two points on the figure lies partly outside the figure.
Convex: A convex figure is one in which a line segment drawn to connect any two points on the figure will have no points outside the figure.
Those definitions can be a bit difficult to understand. In my own words, a concave figure has a CAVE or dent in it. A convex figure doesn't.
Here are examples of each.
The
red line segments on the concave figures show you how such a segment can "fall off." The blue segments do NOT fall off. Notice we can have these blue segments on concave and convex figures. We cannot have the red segments on our convex figures (that wouldn’t follow the definition). Take me home!