1. Classifying Triangles
Subject: Geometry
Grade Level: 7th grade

2. Antonetti Triangle Notes
Fold page in ½
Students will take notes on one side and draw on the other.

3. Where can you find TRIANGLES?
Watch Animoto video!

4. Properties of TRIANGLES?
Watch Discovery Ed video!

5. Two Ways to Classify Triangles
Classify by “Sides”
Scalene
Isosceles
Equilaterial
Classify by “Angles”

6. Classifying Triangles By Their Sides
Scalene
Isosceles
Equilateral

7. No sides are the same length
Scalene Triangles
No sides are the same length

8. At least two sides are the same length
Isosceles Triangles
At least two sides are the same length

9. Equilateral Triangles
All sides are the same length

10. Two Ways to Classify Triangles
Classify by “Sides”
Scalene
Isosceles
Equilaterial
Classify by “Angles”
Acute
Right
Obtuse

11. Classifying Triangles By Their Angles
Acute
Right
Obtuse

12. Acute triangles have three acute angles

13. Right triangles have One right angle

14. Obtuse triangles have ONE obtuse angle

15. Classify this triangle.
Right Scalene

16. Classify this triangle.-
Obtuse Isosceles

17. Classify this triangle.
Acute Scalene

18. Classify this triangle.
Acute Isosceles

19. Classify this triangle.
Obtuse Scalene

20. The sum of the measures of any triangle is 180°.
Triangle Degrees
The sum of the measures of any triangle is 180°.
What is the
measure of x?
70° x

21. Triangle Degrees
What is the
measure of x?
45° x

22. Triangle Degrees x
What is the
measure of x?
60°
50°

23. Side Measures Draw triangles given 3 side measures.
“You Want Me to Do What?!” Worksheet

24. Angle Measures Protractor Practice:
How to Use a Protractor
Independent Practice measuring angles and constructing angles
Construct triangles given (3) angle measures.
“Construct Triangles with Angle Measures” worksheet

25. Classification by Angles Classification by Sides
Create Your Own
On a Scrap sheet of paper you need to:
Draw 3 triangles
3 Different Sizes - Very Precise
Measure Sides and Angles (Label)
Put in a chart (See my example)
Classify Each triangle according to your notes.
Triangle
<1
<2
<3
Sum
Classification by Angles
Side 1
Side 2
Side 3
Classification by Sides 1 2 3

26. Classifying Quadrilaterals

27. Quadrilateral Flowchart
Give Student’s a copy of Flowchart…
Brainstorm with your partner:
Use the word bank to complete the Flowchart?
Rectangle
Rhombus
Trapezoid
Quadrilateral
Parallelogram
Square

28. Quadrilateral Flowchart

29. What is a quadrilateral?
A quadrilateral is a closed 2 dimensional figure with FOUR (4) line segments.

30. What is a parallelogram?
Opposite sides congruent
Opposite sides parallel

31. What is a rectangle?
Four right angles.

32. What is a rhombus?
Four congruent sides.

33. What is a square?
4 right angles
4 sides congruent

34. What is a trapezoid?
Exactly one pair of parallel sides

35. What are all of the names for this polygon?
Quadrilateral
Parallelogram
Rectangle
Which name best describes the shape?

36. What are all of the names for this polygon?
Quadrilateral
Parallelogram
Which name best describes the shape?

37. What are all of the names for this polygon?
Quadrilateral
Parallelogram
Rhombus
Which name best describes the shape?

38. What are all of the names for this polygon?
Quadrilateral
Trapezoid
Which name best describes the shape?

39. What are all of the names for this polygon?
Quadrilateral
Parallelogram
Square
Rhombus
Rectangle
Which name best describes the shape?