Polygon and Convexity Lecture Notes

Vocabulary flashcards covering the properties of polygons, including convexity and the naming conventions based on the number of sides.

Sum of the measures of the angles of a polygon

The value obtained by subtracting 2 from the number of sides, and then multiplying the resulting difference by $180^{\circ}$.

Convex polygon

A polygon where its interior angles are less than $180^{\circ}$ and any line segment connecting any two points inside will remain completely inside the shape.

Non-convex polygon

A polygon that contains one interior angle greater than $180^{\circ}$ and where a line segment connecting certain points inside may have part of the segment outside the shape.

Triangle

A polygon with 3 sides.

Quadrilateral

A polygon with 4 sides.

Pentagon

A polygon with 5 sides.

Hexagon

A polygon with 6 sides.

Heptagon

A polygon with 7 sides.

Octagon

A polygon with 8 sides.

Nonagon

A polygon with 9 sides.

Decagon

A polygon with 10 sides.

$n$-gon

A polygon with $n$ number of sides.