Concave and Convex Shapes

Geometric shapes can be classified as either concave or convex.

What Is a Convex Shape?

A shape is convex if every line segment connecting any two points within it stays entirely inside the shape. In other words, no part of the segment crosses the shape's boundary.

What Is a Concave Shape?

A shape is concave if at least one line segment connecting two points within it extends beyond the shape's boundary.

And so forth.