This document discusses the different types of triangles: equilateral triangles have three equal sides and three equal angles; isosceles triangles have two equal sides; right triangles have one 90-degree angle; and scalene triangles have no equal sides. It also notes that the interior angles of any triangle always sum to 180 degrees, and provides an example of finding a missing angle in a triangle where two angles are given.

1. Triangles

2. Types of Triangles
 Equilateral triangle: three
congruent (equal) sides and three
equal angles
These marks indicate equality.

3. Types of Triangles
 Isosceles triangle: two congruent
(equal) sides

4. Types of Triangles
 Right triangle: Has only one right
angle (90 degrees)
This box indicates a right
angle or a 90-degree angle.

5. Types of Triangles
 Scalene triangle: A triangle that
has no congruent (equal) sides

6. Interior Angles
 Interior angles of a triangle always
equal 180 degrees.

7. Example
 Find the missing angle
96o
39o
xo