The document defines and describes properties and classifications of triangles. It states that a triangle has three sides, the sum of interior angles is 180 degrees, and an exterior angle equals the sum of nonadjacent interior angles. Triangles are classified based on sides as equilateral (three equal sides), isosceles (two equal sides), or scalene (three unequal sides). They are also classified based on angles as acute (three acute angles), right (one 90 degree angle), or obtuse (one obtuse angle).

1. TRIANGLES
Produced by Yanine Wong

2. DEFINITION
OF TRIANGLE
A triangle is a polygon with three
sides.

3. PROPERTIES OF
TRIANGLES
1.- One side of a triangle is less than the
sum of the other two and greater
than their difference.
3
5 3 + 4 = 7 > 5
4 4 – 3 = 1 < 5

4. PROPERTIES OF
TRIANGLES
2.- The sum of the interior angles of a
triangle equals 180 °.
70°
70° + 80° + 30° = 180°
80° 30°

5. PROPERTIES OF
TRIANGLES
3.- The value of an exterior angle is equal
to the sum of the two nonadjacentinterior.
60°
90° + 60°= 150°
90° 150°
30°

6. CLASSIFICATION OF
TRIANGLES
ACCORDING TO ITS SIDES
EQUILATERAL TRIANGLE
THREE EQUAL SIDES.

7. CLASSIFICATION OF
TRIANGLES
ACCORDING TO ITS SIDES
ISOSCELES TRIANGL
E
TWO EQUAL SIDES

8. CLASSIFICATION OF
TRIANGLES
ACCORDING TO ITS SIDES
SCALENE TRIANGLE
THREE UNEQUAL SIDES

9. CLASSIFICATION OF
TRIANGLES
ACCORDING TO THE ANGLES
ACUTE TRIANGLE
THREE ACUTE ANGLES

10. CLASSIFICATION OF
TRIANGLES
ACCORDING TO THE ANGLES
RIGHT TRIANGLE
A RIGHT ANGLE
THE LONGEST SIDE IS THE HYPOTENUSE.
THE SHORTER SIDES ARE THE LEGS.

11. CLASSIFICATION OF
TRIANGLES
ACCORDING TO THE ANGLES
OBTUSE TRIANGLE
AN OBTUSE ANGLE