1. Triangles
TOPIC LESSON 9-5

2. Triangles can be classified by their sides.3
equal
sides
equilateral triangle

3. Triangles can be classified by their sides.2
equal
sides
isosceles triangle

4. Triangles can be classified by their sides.
equal
sides
scalene triangle

5. Triangles can also be classified by their angles.1
right
angle
right triangle
One angle measures 90 degrees. The other 2 are acute or less than 90 degrees.

6. Triangles can also be classified by their angles.3
acute
angles
acute triangle
All angles measure less than 90 degrees.

7. Triangles can also be classified by their angles.1
obtuse
angle
obtuse triangle
One angle measures greater than 90 degrees.

8. Classify this triangle by its sides and angles.

9. 3 equal sides, 3 acute angles
Did you say. . .
equilateral, acute?
3 equal sides, 3 acute angles

10. Classify this triangle by its sides and angles.

11. Did you say . . .
isosceles, right?
2 equal sides, one right angle

12. Classify this triangle by its sides and angles.

13. Did you say . . .
scalene, obtuse? 0 equal sides, 1 obtuse angle

14. Can you classify this triangle by its sides and angles?

15. Did you say . . .
scalene, right?
0 equal sides,1 right angle

16. Classify this triangle by its sides and angles.

17. Did you say. . .
isosceles, acute
2 equal sides, 3 acute angles

18. Now you know how to identify triangles.