Convex polygons

Convex polygons are polygons for which a line segment joining any two points in the interior lies completely within the figure

The word interior is important. You cannot choose one point inside and one point outside the figure

The following figure is convex:




No matter how I choose two points inside this polygon, the line segment joining these two points will always be inside the figure.

Notice that a triangle, isosceles, scalene, right, or obtuse is always convex




Rectangles, squares, and trapezoid too are always convex




Finally, all regular polygons, such as a pentagon, hexagon, septagon, octagon, and so forth are always convex