NEW B.Ed COLLEGENELLIMOODU

THIRUVANANTHAPURAM – 695524

INNOVATIVE LESSON PLAN

(SEMESTER-II)

B.Ed. COURSE 2013 – 2014

SUMI S. V.

MATHEMATICS

180/13376012

Name of the teacher : SUMI S. V. Standard : VIIIName of the School : Division :Name of the Subject : Mathematics Streenght :Name of the Unit : Congruent triangles Duration : 45 mtsName of the sub unit : Isosceles Triangles Date :

Curricular Statement : Understanding the issoscles TrainglesTerms : Isosceles TraingleFacts : A Trinagle in which two sides are equal is called isosceles triangle.Concept : The concept of isosceles trainglePrinciple : 1. If two sides of a triangle are equal, then the angles oppsoite to these sides are also equal.

2. If two angles of a traingles are equal, then the sides opposite these angles are also equal.Process : The process of finding the isoscles triangleLearning outcomesPupil : 1. Remembering the information about the characteristics of isosceles triangle.

2. Develops understanding infinding the isosceles traingle 3. Applying the above information infamiliar situations. 4. Analysing the information to explore understanding and relation. 5. Justify the above concepts and formulas. 6. Creating new ideas related to the above facts and concepts. 7. Develops skills infinding the isosceles trianagle. 8. Develops interests infinding the characteristics of isosceles triamgle.

Pre Requisites : Isosceles triangle, CongruencyTeaching Learning Resources : Activity card, Chart

Classroom Interaction Procedure Pupil ResponsePreparation :

The teacher asks the student to different types of trianglesThe teacher asks the student to the isosceles traingles.The teacher shows the models of traiangles with the help of slides.

TrianglesThe different types of traingles Are

Then the teacher shows the slide of any triangle

Any triangle can be split into two right angled triangles, by drawinga perpendicular from one vertex to opposite side.

A

B P C

Then show the another slide

A triangle with two of its sides equal can be split into two

congruent right angled triangles. We need only draw the

perpendicular from the vertex where the equal sides meet,

to the opposite side.

DevelopmentThe teacher divide the students into four groups and for each group the activity.To draw the triangle in which two sides are equal and then draw perpendicular from the vertexwhere the equal sides meet, to the opposite side.Then the students draw a triangle.

The teacher shows the another slide

In this figure AB = AC in ABC. The line AP is drawn perpendicualr to the side BS. The ABCis divided into two right angled triangles ABP and ACP. They are congruent. So their sides mustbe equal.

P

Then the teacher shows the clear definition of isosceles triangle

Isosceles TraingleIf two sides of a triangle are equal, then the angles opposite to there sides are also equal.

Is the resverse true?That is, if two angles of the triangle are equal, are the sides opposite them also equal?The teacher shows the another slide.

P

In this triangle AP is a common side. And one angle on this side is 900 in both trianglesSince the sum of the angles of any triangles is 1800.

We have in ABP<ABP + <BAP +900 = 1800

from which we get<ABP + <BAP = 900 and hence<BAP = 900 - <ABP

Similarly, from ACP, we get<CAP = 900 - <ACP

If we use the fact that<ABP = <ACP also we get<BAP = <CAP

Thus the side AP of ABP and the angles APB and BAP on it are equal to the side AP ofACP and the angles APC and CAP on it. So the triangles are congruent.

P

Then the teacher shows the another slide.

If two angles of a traingle are equal, then the sides opposite these angles are also equal

From the slide they reach the concept of a triangle in which two sides are equal. This triangle is calledisosceles triangleTo check whether the students understand the concept the teacher given a problem.

P

Application1. Find the other two angles of the isoceles triangle

From the isosceles triangleTwo sides are equal so the sides opposite angles are equal180 - (33+33) = 180 - 660 = 1140

Review1. What are the properties of isoscles triangle?Follow up Activity :1. Find the other two angles?What are the angles of an isosceles right angled triangle.

330

500