Sum of Interior Angles of a Triangle

Sum of Interior Angles of a Triangle

Learning Objectives

At the end of the lesson, you will understand that the sum of the interior angles of a triangle is always 180 degrees. At the end of the lesson, you will be able to demonstrate the sum of the interior angles of a triangle through hands-on activities.

What do you already know about the interior angles of a triangle?

Introduction to the properties of triangles

The lesson aims to teach that the sum of the interior angles of a triangle is 180 degrees through a hands-on activity.

Hands-on activity to explore the sum of interior angles

Students will cut out a triangle, tear off the corners, and then align these corners to form a straight line, effectively demonstrating that the angles sum up to 180 degrees.

Proof of the sum of interior angles of a triangle

Students will explore the concept of straight angles and how they relate to the sum of interior angles in a triangle.

Definition List

Interior Angles of a Triangle: the angles found at the vertices inside the triangle; Straight Angle: an angle that measures 180 degrees

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.