Transcript Introduction to Polygons - Greer Middle College Charter

Introduction to Polygons
Vocabulary
• Polygon: a closed plane figure made of line
segments
• Convex Polygon: the measures of all interior
angles are less than 180°
• Concave Polygon: the measure of at least one
interior angle is greater than 180°
• Regular Polygon: all angles and sides are
congruent
Classifying Polygons
In math, one of the ways we classify shapes is by the number of sides
they have:
Number of Sides
Name
3
triangle
4
quadrilateral
5
pentagon
6
hexagon
7
heptagon
8
octagon
9
nonagon
10
decagon
11
11-gon
12
dodecagon
13
13-gon
…
…
117
117-gon
Exterior and Interior Angles of
Polygons
ACTIVITY