Notes: 6.1
Each segment that forms a polygon is a___side______________
The common endpoint of two sides is a ___vertex_____________
A segment that connects any two nonconsecutive vertices is a
___diagonal_________
You can name a polygon by the number of its sides.
Complete the table to the right.
Number of sides
Polygon
Triangle
3
Quadrilateral
4
Pentagon
5
Hexagon
6
Heptagon
7
Octagon
8
Nonagon
9
Decagon
10
Dodecagon
12
n-sided polygon
n
Remember!! A polygon is a closed plane figure formed by three or more segments that intersect only at
their endpoints.
Tell whether the figure is a polygon. If it is a polygon, name it by the number of sides.
Yes, hexagon
Yes, Heptagon
No!
All the sides are congruent in an equilateral polygon. All the angles are congruent in an equiangular
polygon. A _Regular
polygon is one that is both equilateral and equiangular. If a polygon is
not regular, it is called __Irregular_______________.
A polygon is __concave_______ if any part of a diagonal
contains points in the exterior of the polygon.
If no diagonal contains points in the exterior, then the polygon is
___convex________.
A _regular__________ polygon is always convex.
Tell whether the polygon is regular or irregular. Tell whether it is concave or convex Name the
polygon according to the number of sides.
Quadrilateral
Irregular
Convex
Dodecagon
Irregular
Concave
Quadrilateral
Irregular
Concave
Ex. Find the sum the interior angle measures of a convex pentagon (5-2)180=540
Find the sum of the interior angle measures of a convex heptagon. (7-2)(180)= 900
*REMEMBER If regular polygon then all angles are congruent
To find EACH interior angle- find the sum and then divide by # of sides
Find the measure of each interior angle of a regular 16-gon. ( (16-2)(180))/ 16= 157.5
The sum of the exterior angle on any polygon always measures is ___360____.