4. 2. Concave and convex polygons
• A convex polygon has no internal angle
more than 180º and if there are any
internal angles greater than a straight
angle, then it is a concave polygon.
6. 3. Regular and Irregular polygons
• Regular polygon is one whose sides are all
equal and whose interior angles are all
congruent. Thus, a regular polygon is both
equilateral and equiangular. If, otherwise, the
polygon is said to be irregular polygon.
15. • To construct a polygon’s name, combine the
corresponding prefix and suffix.
Example:
Construct the name for 28 and 46 sided
polygons.
Sides Prefix
20
Icosa
Sides Suffix
8 Octagon
Icosaoctagon