Polygon Characteristics Quiz & Flashcards

Study Notes

A polygon is a two-dimensional object consisting of a sequence of at least three segments of a line, with each segment sharing a common endpoint with the next.
The endpoints of the segments are called vertices, and the segments themselves are called sides or edges.
Each pair of consecutive sides of a polygon determines two angles: an interior angle and an exterior angle.

A polygon can be classified as regular, irregular, concave, convex, simple, or complex.
Regular polygons have congruent sides and interior angles.
Irregular polygons have at least one pair of sides or interior angles that are not congruent.
Concave polygons have a segment with endpoints inside the polygon and points on the segment that are outside the polygon.
Convex polygons have any two interior points that determine a segment of line totally contained in the polygon.
Simple polygons have segments that intersect only at vertices, while complex polygons have segments that intersect at points that are not vertices.

Figure 1 shows examples of regular, irregular, concave, convex, simple, and complex polygons.
Figure 2 shows an isosceles triangle that is irregular.
Figure 3 shows a convex quadrilateral and a concave hexagon.
Figure 4 shows a simple polygon and a complex polygon.

A circle is not a polygon because it is not made up of straight line segments.
Shapes with sides that are not straight, shapes that are not closed, and three-dimensional shapes are not polygons.
Figure 5 shows examples of shapes that are not polygons, including a circle, a shape with a curved side, a shape that is not closed, and a three-dimensional shape.