2. “…geometric shapes are the alphabet in which the book of nature is written." -Galileo

3.   You are learning to classify quadrilaterals. Objectives

4. Point - A place in time or space Line - a series of points that extends forever Figure - a line or shape that represents something

5. Point - A place in time or space Line - a series of points that extends forever Figure - a line or shape that represents something

6. Point - A place in time or space Line - a series of points that extends forever Figure - a line or shape that represents something

7. Point - A place in time or space Line - a series of points that extends forever Figure - a line or shape that represents something

8. Shape - A closed figure Polygon - A closed plane figure. Straight edges Point - A place in time or space Line - a series of points that extends forever Figure - a line or shape that represents something

9. Shape - A closed figure Polygon - A closed plane figure. Straight edges

10. Shape - A closed figure Polygon - A closed plane figure. Straight edges

11. Shape - A closed figure Polygon - A closed plane figure. Straight edges

12. Shape - A closed figure Polygon - A closed plane figure. Straight edges

13. Shape - A closed figure Polygon - A closed plane figure. Straight edges

14. Shape - A closed figure A closed plane figure. Straight edges Polygon- A closed plane figure. Straight edges

15. A closed plane figure. Straight edges Polygon - A closed plane figure. Straight edges

16. A closed plane figure straight edges Polygon - A closed plane figure. Straight edges Quadrilateral-

17. A closed plane figure straight edges Polygon - A closed plane figure. Straight edges

18. Quadrilateral - A closed plane figure straight edges Polygon - A closed plane figure. Straight edges four

19. Polygon - A closed plane figure. Straight edges Quadrilateral - A closed plane figure straight edges four

20. Quadrilateral - A closed plane figure four straight edges

21. Quadrilateral - A closed plane figure four straight edges

22. Quadrilateral - A closed plane figure four straight edges

23. Quadrilateral - A closed plane figure four straight edges

24. Quadrilateral - A closed plane figure four straight edges

25. Quadrilateral - A closed plane figure four straight edges every single one of these polygons.

26. Like other polygons, quadrilaterals have properties. We can look at the length of the sides. We can look at the size of the angles We look to see if opposite sides are parallel We look to see if opposite sides are congruent angle-measures how far a figure has rotated around a point congruent-exact same shape-exact same size parallel-lines that never meet obtuse-an angle greater than 90 acute-an angle less than 90 right-an angle equal to 90 acute right obtuse

27. Like other polygons, quadrilaterals have properties. angle-measures how far a figure has rotated around a point congruent-exact same shape-exact same size parallel-lines that never meet obtuse-an angle greater than 90 acute-an angle less than 90 right-an angle equal to 90 We classify quadrilaterals into groups that have similar properties. classify-organize into groups based on properties Similar-same figure could be different size These groups are called parallelograms rectangles square irregular rhombi (Plural for rhombus) trapezoids Kite or diamond para lel ogram parallelogram

28. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

29. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

30. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

31. Parallelograms Our biggest group is the parallelograms. Opposite sides are parallel. Let’s look at the property that makes a quadrilateral a parallelogram

32. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

33. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

34. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

35. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

36. Parallelograms Our biggest group is the parallelograms. Let’s look at the property that makes a quadrilateral a parallelogram Opposite sides are parallel.

37. acute right obtuse Parallelograms Opposite sides are parallel. Rectangles There are special parallelograms we call rectangles. Four right angles So we look at another property

38. Parallelograms Opposite sides are parallel. Rectangles There are special parallelograms we call rectangles. Four right angles So we look at another property

39. Parallelograms Opposite sides are parallel. Rectangles Four right angles

40. Parallelograms Opposite sides are parallel. Rectangles Four right angles A square is a rectangle that has congruent sides All four sides are exactly the same size Square

41. Parallelograms Opposite sides are parallel. Rectangles Four right angles A square is a rectangle that has congruent sides All four sides are exactly the same size Square

42. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square

43. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square There is one more type of parallelogram. It is called a rhombus

44. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square There is one more type of parallelogram. It is called a rhombus Rhombus

45. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus Square Four sides are congruent

46. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus Square Four sides are congruent But does not need four right angles

47. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus Square But does not need four right angles

48. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus Square But does not need four right angles

49. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus Square But does not need four right angles

50. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. They are not parallelograms

51. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. They are not parallelograms

52. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid Trapezoids are pretty easy. They only need one pair of parallel lines That’s it, no more rules! Just add two more lines and you have a trapezoid.

53. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid Trapezoids are pretty easy. They only need one pair of parallel lines That’s it, no more rules! Just add two more lines and you have a trapezoid.

54. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines So, is a square a trapezoid?

55. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines So, is a square a trapezoid? Yes No Click one.

56. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines So, is a square a trapezoid?

57. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines So, is a square a trapezoid? Of course it is! Squares are so cool!

58. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines Now, the last named quadrilateral. This one has two rules. One right angle. Two pair of congruent lines

59. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines Now, the last named quadrilateral. This one has two rules. One right angle. Two pair of congruent lines What does it look like?

60. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines What does it look like? Could it be a kite?

61. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines Could it be a kite?

62. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines Could it be a kite?

63. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Some definitions of kite do not require a right angle.

64. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Some definitions of kite do not require a right angle.

65. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Now let’s talk about two more types of quadrilaterals. Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Some definitions of kite do not require a right angle.

66. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines The rest of the quadrilaterals we see are irregular

67. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines The rest of the quadrilaterals we see are irregular

68. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Irregular

69. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Rhombus Square But does not need four right angles Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Irregular

70. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus But does not need four right angles Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Irregular Quadrilaterals

71. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus But does not need four right angles Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Irregular Quadrilaterals

72. Parallelograms Opposite sides are parallel. Rectangles Four right angles Four sides are congruent Square Rhombus But does not need four right angles Trapezoid They only need one pair of parallel lines Kite or Diamond One right angle. Two pair of congruent lines Irregular Quadrilaterals