1. Bell Work Name the Angle in four different waysC
vertex
side 1
1) Use the vertex and a point from each side.
ABC or
CBA
The vertex letter is always in the middle.
2) Use the vertex only. B
This only works if there is only one angle at a vertex.
3) Use a number. 1

2. Classifying Triangles

3. 2 Ways to Classify By Side Length By Angle Measurement Equilateral
Isosceles
Scalene
By Angle Measurement
Right
Obtuse
Acute

4. Side Length Equilateral
An Equilateral triangle is a triangle where all three side lengths are congruent.
The dashes on the sides of the triangle mean they are the same length (congruent).
Remember: Congruent just means equal is the symbol used for congruent.

5. Side Length Isosceles
An isosceles triangle is a triangle where at least two sides are congruent.
The dashes on the sides of the triangle mean they are the same length (congruent).

6. Side Length Scalene
A scalene triangle is a triangle where all three sides have different measures.
The different numbered dashes on the sides of the triangle mean they are all different lengths.

7. Angle Measurement Right
A right triangle is a triangle that has exactly one right angle.
The box in the corner of a triangle represents a right angle. Remember that a right angle is an angle that measures 90⁰.

8. Angle Measurement Obtuse
An obtuse triangle is a triangle that has exactly one obtuse angle. Remember that an obtuse angle is an angle that is greater than 90⁰.

9. Angle Measurement Acute
An acute triangle is a triangle where all three angles are acute. Remember that an acute angle is an angle that is less than 90⁰.

10. Equiangular Triangle
A triangle with all angles equal (60°). The same as an Equilateral Triangle

11. You Try: Obtuse Isosclese Triangle
Name the triangle by its angles and sides
Obtuse Isosclese
Triangle

12. Right Scalene Triangle
You Try:
Name the triangle by it’s angles and sides
Right Scalene Triangle

13. Video

14. We will grade these with ABCD cards at the end of class!
Practice: Worksheet
We will grade these with ABCD cards at the end of class!