Polygons and Quadrilaterals (Unit 7)

polygon

a closed figure bounded by three or more line segments

vertices

the endpoints of each side of a polygon

diagonal

a segment joining two nonconsecutive vertices of a polygon

triangle

3 sided polygon

quadrilateral

4 sided polygon

pentagon

5 sided polygon

hexagon

6 sided polygon

heptagon

7 sided polygon

octagon

8 sided polygon

nonagon

9 sided polygon

decagon

10 sided polygon

dodecagon

12 sided polygon

n-gon

n sided polygon

regular polygon

a polygon that is equilateral and equiangular

exterior angle of a polygon

an angle between any side of the polygon and a line extended from the next side

the sum of the measures of the interior angles of a polygon with n sides

(n-2) * 180

each interior angle of a regular polygon with n sides

(n-2) * 180 / n

the sum of the measures of the exterior angles of any polygon

360

each exterior angle of a regular polygon with n sides

360 / n

convex polygon

a polygon where all interior angles are less than 180, and the vertices are pointing outwards

concave polygon

polygon has at least one interior angle greater than 180 - at least one vertex is pointing inwards

square

a quadrilateral with congruent, perpendicular, and bisecting diagonals

rectangle

a parallelogram with 4 right angles and congruent, bisecting diagonals

parallelogram

a quadrilateral with two pairs of congruent opposite angles

rhombus

a parallelogram with four congruent sides