THE WORLD OF POLYGONS LESSON 4

ACTIVITY:BIRDSEYE VIEW

ACTIVITY:BIRDSEYE VIEW

ACTIVITY:BIRDSEYE VIEW

ACTIVITY:BIRDSEYE VIEW IS SHAPE 1 A POLYGON?

ACTIVITY:BIRDSEYE VIEW IS SHAPE 2 A POLYGON?

ACTIVITY:BIRDSEYE VIEW IS SHAPE 3 A POLYGON?

DEFINITION Polygon, in geometry, a 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 ARE NAMED AND CLASSIFIED ACCORDING TO THEIR NUMBER OF SIDES.

EXAMPLES TRIANGLE RECTANGLE PENTAGON

EXAMPLES HEXAGON

REGULAR POLYGONS 6 SIDES 3 SIDES 4 SIDES 5 SIDES 7 SIDES 8 SIDES

REGULAR POLYGONS ALL ANGLES ARE EQUAL and ALL SIDES ARE EQUAL.

All polygons have an equal number of sides and vertices. 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.

Polygons are also classified as CONVEX and NONCONVEX.

What is the difference between CONVEX and NONCONVEX POLYGONS?

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 .

EXERCISES TELL WHETHER OR NOT EACH OF THE FOLLOWING IS A POLYGON.

QUIZ TELL WHETHER A POLYGON IS CONVEX OR NOT.

POLYGONS LESSON 5

All polygons have an equal number of sides and vertices. RECALL All polygons have an equal number of sides and vertices.

TRIANGLE QUADRILATERAL PENTAGON HEXAGON HEPTAGON OCTAGON NONAGON DECAGON

POLYGON PARTS

Side - one of the line segments that make up the polygon. POLYGON PARTS Vertex - point where two sides meet. Two or more of these points are called vertices. Side - one of the line segments that make up the polygon.

Diagonal - a line connecting two vertices that isn't a side. POLYGON PARTS Diagonal - a line connecting two vertices that isn't a side.

POLYGON PARTS Exterior Angle - Angle formed by two adjacent sides outside the polygon. Interior Angle - Angle formed by two adjacent sides inside the polygon.

TRIANGLE