simple closed two-dimensional figure formed by the joining of three or more straight line segments, called SIDES.
DEFINITION
A figure is simple if it extends in no more than two directions from any point and closed if its starting point is the same as its endpoint.
DEFINITION
These restrictions require that the sides of a polygon not cross each other and that pairs of sides intersect at their ENDPOINTS, which are called VERTICES.
POLYGONS POLYGONS ARE NAMED AND ARE NAMED AND
CLASSIFIED CLASSIFIED ACCORDING TO ACCORDING TO
THEIR NUMBER OF THEIR NUMBER OF SIDES.SIDES.
EXAMPLESTRIANGLE RECTANGLE
PENTAGON
EXAMPLESHEXAGON
REGULAR POLYGONS3 SIDES 4 SIDES 5 SIDES 6 SIDES
7 SIDES 8 SIDES 9 SIDES 10 SIDES
REGULAR POLYGONSALL ANGLES ARE EQUAL and ALL SIDES ARE EQUAL.
REMEMBER
All polygons have an equal number of sides and vertices.
EXAMPLE
TRIANGLE
- 3 SIDES.- 3 VERTICES- 3 ANGLES
Polygons are also classified as CONVEX and NONCONVEX.
NONCONVEX
Polygons are also classified as CONVEX and NONCONVEX.
CONVEX
What is the difference between CONVEX and NONCONVEX
POLYGONS?
CONVEX
NONCONVEX
A POLYGON IS CONVEX IF A
SEGMENT JOINING ANY 2 POINTS OF
THE POLYGON LIES COMPLETELY
INSIDE THE POLYGON.
CONVEX
OTHERWISE THE POLYGON IS NONCONVEX .
NONCONVEX
EXERCISES• TELL WHETHER OR NOT EACH
OF THE FOLLOWING IS A POLYGON.
QUIZ• TELL WHETHER A POLYGON IS
CONVEX OR NOT.
POLYGONSPOLYGONSPOLYGONSPOLYGONSLESSON 5LESSON 5
RECALL
All polygons have an equal number of sides and vertices.