2. Triangles Galore!

3. Classification By Angle
Acute triangle
Obtuse triangle
Right triangle

4. Acute Triangles An acute triangle has only acute angles.
What could another combination of angles be for an acute triangle?

5. Obtuse triangle An obtuse triangle has one obtuse angle.
Can a triangle have more than two obtuse angles?

6. Right Triangle A right triangle has only one right angle.
Can a right triangle also be an acute triangle?

7. 180o When you add all the angles of any triangle they add up to 1800.
We proved this in yesterdays lab! Tear the corners off of a triangle, connect them together using their smooth sides and see what it makes.

8. Find the unknown angle then classify it.60 90 60 60

9. Classification by Sides
Equilateral triangle
Isosceles triangle
Scalene triangle

10. What does it mean to be congruent?
Sides of a shape are congruent if they are the same length. You can use tick marks to show congruent sides.

11. Scalene Triangle A scalene triangle has no congruent sides.
If a triangle has no congruent sides, what do you know about it’s angle measurements?

12. Isosceles Triangle
An isosceles triangle has at least two congruent sides.
Can a right triangle also be isosceles?

13. Equilateral Triangle
An equilateral triangle has three congruent sides.
Draw an example of an equilateral triangle and label the side measurements.

14. Let’s Classify!
Classify the triangles by there angles and sides

15. Try this one!
The perimeter of the triangle is 24 cm. Classify the triangle. 8 8

16. Try this one!
The perimeter of the triangle is 30 ft. Classify the triangle.
6ft.
12 ft.