1. Polygons and Quadrilaterals

2. Polygons
The word polygon means “many angles”

3. What is a Polygon? A closed figure
Made up of three or more straight lines
The sides do not cross each other

4. These are polygons

5. These are Not Polygons because. . .
Lines are not straight
Only two lines
Lines Cross
Not Closed

6. A pentagon has five sides.1 5 2 4 3

7. Hexagon and Heptagon
A hexagon has six sides. (Hexagon and six both have an “x”.)
A heptagon has seven sides.
heptagon
hexagon

8. Octagon
An octagon has eight sides. Count the sides.

9. Nonagon 9 sides

10. Decagon Ten Sides

11. Let’s Review: A pentagon has five sides. A hexagon has six sides.
A heptagon has seven sides.
An octagon has eight sides.
A nonagon has nine sides
A decagon has ten sides

12. Quadrilaterals
parallelogram
rectangle
trapezoid
square
rhombus

13. Definition
Quadrilateral – a polygon with 4 angles and 4 straight sides.

14. Each shape has four sides.
Quadrilaterals
“Quad” means four. Why would all of these shapes be called “quadrilaterals”?
Each shape has four sides.
trapezoid
square
rhombus
parallelogram
rectangle

15. The angles add up to 360º
65º
65º
115º
65º
115º
115º +
65º
115º
360º

16. Square A square has four sides that are each the same length.
It also has four right angles (perfect corners). 1 4 3 2

17. Rhombus A rhombus has four sides that are each the same length.
But it has two acute and two obtuse angles.
obtuse
acute
acute
obtuse

18. Square and Rhombus
A square and a rhombus both have four sides that are the same length. So, how are they different?

19. Square and Rhombus A rhombus can be thought of as a slanted square.
If we push on the left-hand side of this square, it might end up looking like…
a rhombus.

20. The only difference between a square and a rhombus is their angles.

21. Trapezoid A trapezoid has four sides. Two sides are parallel.
The opposing two sides are not parallel.
Those are not parallel.
Those are parallel.

22. Rectangle
A rectangle has four sides – two long sides and two short sides.
Two sides are parallel.
The opposing two sides are also parallel.
It also has four right angles.

23. Parallelogram
A parallelogram has four sides – two long sides and two short sides.
Two sides are parallel.
The opposing two sides are also parallel.
But, it has two acute and two obtuse angles.

24. Rectangle and Parallelogram
A parallelogram can be thought of as a slanted rectangle.
If we push on the left-hand side of this rectangle, it might end up looking like…
a parallelogram.

25. The only difference between a rectangle and a parallelogram is their angles.

26. Quadrilaterals SHAPE SIDES ANGLES PARALLEL LINES Square 4 same length
4 right angles
2 sets
Rhombus
2 acute
2 obtuse
Trapezoid
different lengths
different angles
1 set
Rectangle
2 long,
2 short
Parallelogram

27. Now that you are done, go to the websites to play the games