Introduction

1. Introduction Topic: Classifying Triangles

2. Objective Students will identify, describe, and compare triangles: isosceles, right, equilateral, scalene, obtuse, and acute.

3. Materials • Brainpop Movie on triangles http://www.brainpop.com/math/geometryandmeasurement/typesoftriangles/ • Promethean Flipchart :Classifying Triangles • Illuminations: Resources for Teaching Math Lesson on “What’s so important about Triangles?”    • Grid paper • Tape

4. Explanation of the Concept

5. Equilateral Triangle • A triangle which has all three of its sides and angles equal in size.

6. Isosceles Triangle • A triangle which has two of its sides and angles equal in size.

7. Scalene Triangle: A triangle which has all of its sides different in size.

8. Right-angled Triangle • A right triangle or right-angled triangle is a triangle in which one angle is a right angle (that is, a 90-degree angle).

9. Acute-angled Triangle An acute-angled triangle has all angles less than 90º (i.e. all three angles are acute).

10. Obtuse-angled Triangles An obtuse-angled triangle has one angle greater than 90º.  That is, one angle is obtuse.

11. Instructions • Create different triangles with specified measurements using grid paper and tape. • Label the triangles with the letters. • Also identify the type of triangle they made.

12. Wrap up (plenary) • Think of any one rule about triangles.