1. 3.6 Types of Triangles Objective:
After studying this lesson you will be able to name the various types of triangles and their parts.

2. Definition:. a scalene triangle is a triangle in which no
Definition: a scalene triangle is a triangle in which no two sides are congruent.
Definition: an isosceles triangle is a triangle in which two sides are congruent. C A B
In triangle ABC, BC is the called the base, angles B and C are called base angles. Angle A is called the vertex angle.

3. Definition:. an equilateral triangle is a triangle in which
Definition: an equilateral triangle is a triangle in which all sides are congruent.
Definition: an equiangular triangle is a triangle in which all angles are congruent.

4. Definition:. an acute triangle is a triangle in which all
Definition: an acute triangle is a triangle in which all angles are acute. 80 60 40
Definition: a right triangle is a triangle in which one of the angles is a right angle. The side opposite the right angle is called the hypotenuse. The sides that form the right angle are called the legs.
hypotenuse
leg
leg

5. Definition:. an obtuse triangle is a triangle in which one
Definition: an obtuse triangle is a triangle in which one angle is obtuse.
112 32 36
Given:
Prove: A 70 B C D

6. F G E H
Given:
Prove:

7. Given: Prove: Reason Statement J O P K M 1 3 2 4 1. 2. 3. 4. 5. 6. 7.8. 9. 1. 2. 3. 4. 5. 6. 7. 8. 9.

8. Summary:
Name the different types of triangles and their characteristics by which we classify them?
Homework: worksheet