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=Learning Objectives=
=Learning Objectives=
==Teaching Outlines==
==Teaching Outlines==
== Concept #1. Formation of a Triangle, elements of a triangle and its measures ==
====Activities====
# A triangle is a three sided closed figure.
# It is one of the basic shapes in geometry.
# It triangle is a polygon with three edges and three vertices.
# There are three angles in a triangle formed at the three vertices of the triangle.
Pre-requisites/ prior competencies
# Interior and exterior angles in a triangle at a vertex, together form a linear pair.
Resources needed (digital and non-digital)
How to do the activity (both hands-on steps and discussion questions)
==== '''Activity No # 1 : Formation of a triangle''' ====
Evaluation at the end of the activity
[[File:Triangle formation.png|thumb|Formation of a triangle]]
* '''Objectives'''
# Understand formation of triangles
# Recognize elements of triangle
# Introduce concepts of exterior angle.
* '''Pre-requisites'''
Prior knowledge of point, lines, angles, parallel linesResources needed
* '''Resources needed'''
# Digital : Computer, geogebra application, projector.
# Non digital : Worksheet and pencil
# Geogebra files : “[https://www.geogebra.org/m/smnvwasa 1.Introduction to a triangle.ggb]”
* '''How to do'''
# Use the geogebra file to illustrate.
# How many lines are there? Are the lines meeting?
# Are the two lines parallel? How can you say they are parallel or not?
# How many angles are formed at the point of intersection?
# What is the measure of the total angle at the point of intersection of two lines?
# Of the four angles formed which of the angles are equal? What are they called?
# Do the three intersecting lines enclose a space? How does it look? It is called a triangle.
# What are the points of intersection of these three lines called?
# The line segments forming the triangle are called sides.
# How many angles are formed when three lines intersect with each other?
# How many angles are enclosed by the triangle?
* '''Evaluation at the end of the activity'''
# Can there be a closed figure with less than three sides?
# Can the vertices of the triangle be anywhere on a plane?
# What will happen if the three vertices are collinear?
[[Category:Triangles]]
[[Category:Triangles]]
[[Category:Class 9]]
[[Category:Class 9]]
