Elements of a triangle

Name of the activity

Brief blurb describing what the activity. If this has been borrowed from some external web site (for example, a non OER or OER site which had this idea and based on which the activity was developed)

Objectives

To understand the elements of a triangle

Prerequisites/Instructions, prior preparations, if any

Prior knowledge of point, lines, angles, parallel lines

Materials/ Resources needed

1. Digital : Computer, geogebra application, projector.
2. Non digital : Worksheet and pencil,6-8 strings (preferably in different colours)
3. Geogebra files : “Elements of a triangle.ggb”

Process (How to do the activity)

1. Students work individually but in their groups.
2. Take the strings and place them in such a way as to make a closed figure.
3. What is the smallest number of strings with which you can form a closed figure?
4. What is this figure called?
5. Can you just draw the lines along the strings and see what you get?
6. When you drew, what did you draw?  (Was it a line or was it an angle or was it a line segment?). It is a lime segment – how many line segments are there?
7. When two line segments joined, what is it called?  (A vertex). How many vertices are there?
8. Is there any angle formed when you made this figure? How many angles were formed?
9. Show a simple Geogebra file with triangles – Use this file to demonstrate that every triangle has the elements - vertices, sides and angles
10. How many triangles were formed?  Were there any strings left over?
11. For each of the triangles trace the shape on the book and write down the elements of the triangle in the following format

Vertices	Sides	Angles

12.For each of the triangles observe (inspect visually) which is the longest side and which is the shortest side