Lessons 12.1 and 12.3Describe Plane Shapes and

Identify Polygons

Lesson Opening

In your math notebook describe (using words) the two shapes below.

Plane Shapes

Both of these shapes are

PLANE SHAPES

or shapes on a flat surface.

Closed Shapes

This is a closed shape, or a shape that starts and ends at the same

point.

Closed Shapes

These are all closed shapes.

Open Shapes

This is an open shape, or a shape that does NOT start and end at the same point.

Open Shapes

These are all open shapes.

Polygons

Some closed shapes are made up of only line segments. These shapes are called polygons.

Polygons

Some closed shapes are made up of only line segments. These shapes are called polygons.

This polygon has 5 line segments.

1

2

3

4

5

Polygons

Some closed shapes are made up of only line segments. All of these shapes are polygons.

Describe this shape

Describe this shape

• Plane Shape• Closed Shape• Polygon• Made up of 5 line segments

Describe this shape

Describe this shape

• Plane Shape• Closed Shape

Polygons

A closed shape that is made up only of line segments.

– A triangle is a polygon with 3 sides (or 3 line

segments).

– A quadrilateral is a polygon with 4 sides (or 4

line segments).

– A pentagon is a polygon with 5 sides (or 5 line

segments).

– A hexagon is a polygon with 6 sides (or 6 line

segments).

– A octagon is a polygon with 8 sides (or 8 line

segments).

Describe this shape

Describe this shape

• Plane Shape• Closed Shape• Polygon• Quadrilateral (4 sides)

Describe this shape

Describe this shape

• Plane Shape• Closed Shape• Circle

Describe this shape

Describe this shape

• Plane Shape• Closed Shape• Polygon• Hexagon (6 sides)

Describe this shape

Describe this shape

• Plane Shape• Closed Shape• Polygon• Pentagon (5 sides)

Review of what we have learnedPlane Shapes

(2-dimensional shapes)

Closed Shapes

Not Polygons(circles,

shapes with curved lines)

Polygons

Triangles

(3 sides)

Quadrilaterals

(4 sides)

Pentagons

(5 sides)

Hexagons

(6 sides)

Octagons

(8 sides)

Other Polygons

Open Shapes

Exit Ticket 1. Which terms describe

the shape below?

a. Plane shapeb. Closed shapec. Open shaped. Polygone. Trianglef. Quadrilateralg. hexagon

2. Select all the terms that describe BOTH figures below.

a. Closed shapesb. Open shapesc. Plane shapesd. Polygonse. Trianglesf. quadrilateralsg. pentagons