SCHOOL: Leocadio Alejo Entienza High School GRADE LEVEL: 8

TEACHER: Leonardo P. Albor LEARNING AREA: Mathematics

Date & Time: March 11, 2024 QUARTER: 4, WEEK 1, DAY 1
12:45 pm-1:45pm,1:45pm-2:45pm, and 3:45pm-4:45 pm
I. OBJECTIVES
A. Content Standards The learner demonstrates understanding of key concepts of inequalities in a triangle.
B. Performance Standards The learner is able to communicate mathematical thinking with coherence and clarity
in formulating, investigating, analyzing, and solving real-life problems involving
triangle inequalities.
C. Learning Competencies The learner illustrates theorems on triangle inequalities.
LC CODE
M8GE-IVa-1
a. OBJECTIVES At the end of the lesson, the students are expected to:
1. identify the corresponding sides and corresponding angles of the given triangles,
2. Show the corresponding parts of the given triangles and triangle congruent
statements.
3. Evaluate the corresponding parts of congruent triangles.
4. Appreciate the quality in daily living.
II. CONTENT Illustrating Exterior Angle Inequality Theorem
III. LEARNING RESOURCES
A. References
1. Teacher’s Guide pages pp. 434 - 436
2. Learner’s Material pages pp. 400 - 402
3. Textbook pages Math Builders pp. 329 - 331
4. Additional Materials from https://youtu.be/bWJOJLwznzM?si=436ApcFF3gvVTZLt
Learning Resources
(LR Portal)
B. Other Resources Laptop, Chalk & Chalkboard, YouTube, laptop, manila paper, Carolina, marker.
IV. PROCEDURES
A. Routinary Activity Teacher’s Activity Student’s Activity
Preliminary Activities

1. Opening Prayer

May we all stand and let us ask the

guidance of our almighty God.

So, who would like to lead a prayer? Sir (raising his/her hand).
Anyone?

Ok. In the name of the father the son the holy

spirit Amen. (The students bow their
head)

Heavenly Father and Your Beloved Son

Jesus Christ, thank you for another life to
enjoy, another day to learn, and a new set
of things we will experience. As we go
through our lesson’s today, let us be your
instrument to do good things. Help us to
be obedient, honest, and kind to one
another. These we ask through Christ, our
Lord, Amen.
 Good morning, Sir, we are doing good
2. Greetings Sir.

Good morning class! How are you today?

Okay, I am so glad to hear that! (Students will arrange their chairs and
will pick up the trashes.
Before you sit, kindly align your chairs
and pick up all the trash on the floor.
Yes Sir.
Are you done class?
Thank you, Sir.
Okay thank you! You may now take you
seats.

3. Checking of Attendance

So, class before we proceed in our lesson

for today, let me check the attendance
first.

Is anyone absent from the class? None Ma’am.

Very good! perfect attendance!

No one will miss our very interesting
discussion this morning/afternoon.

4. Ensuring the classroom is

clean/House rules.

Everyone picks up all the trash under

your chair and arrange your chair
properly.

B. MOTIVATION & Individual Activity.

REVIEW:
IN OR OUT Student Response:
There are 3 corresponding angles and 3
corresponding sides which are also
congruent.

Complete the Table

Congruence
statement
Corresponding
angles
Corresponding sides
Students response:
∆ CAT ≅ ∆ NEL Congruence Corresponding Corresponding sides
∆ DCP ≅ ∆ MST statement angles

∠C ↔∠ N
∆ CAT ≅ ∆ NEL CA ↔ NE
∠ A ↔∠ E AT ↔ EL
∠T ↔∠ L CT ↔ NL
∠ D ↔∠ M
∆ DCP ≅ ∆ MST DC ↔ MS
∠C ↔∠S CP↔ ST
∠ P ↔∠ T DP ↔ MT
A.PRESENTATION OF THE ACTIVITY (5 minutes)
LESSON and Establish a On the same group
purpose for the lesson
Tatay Arnold is a welder and he made a
truss for his house. Let’s identify if the
side of the truss are congruent.

Students response :

B. Presenting of new the Remember ME

lesson
 The symbol “↔ is read as
“correspond to”

C ↔ O is read as “vertex C correspond to

vertex O”
CA ↔OF is read as side “ CA
correspond to side OF”

 Two angles are congruent if and only

if their vertices can be paired so that
corresponding sides and
corresponding angles are congruent
 Corresponding parts of congruent
triangles are congruent.

C.Discussing new concepts Example 1

and practicing new skills Answer:
#1 A. Given that ∆ AIM ≅ ∆ SET list down
 the corresponding parts. Corresponding Angles

∠ A ↔∠ S
∠ I ↔∠ E
∠ M ↔∠T
Corresponding Sides
AI ↔ SE
ℑ↔ ET
AM ↔ ST

B. Name the congruent triangle with the

following congruent corresponding parts. Answer:

∠ M ≅∠C ,∠ A ≅∠ P ,∠T ≅∠U ∆ MAT ∧∆ CPU

MA ≅ CP , AT ≅ PU , MT ≅ CU

Example 2

A, Given:∆ IEF ≅ ∆ HGF

Find: ∠ H
Answer: ∠ H=40 °

Reason: ∠ H ≅ ∠ I

B, Given: ∆ ABC ≅ ∆ ADC

Find: y

Solution: Since AB≅ AD

3 y=18
3 y 18
=
3 3
y=6

For their activity I will group the class

into 4 and every group will solve each of
example I gave.
D.Discussing new concepts Example 3:
and practicing new skills
#2 Given that ∆ MYX ≅ JAN ,
∠ M =40 °∧∠ A=70 ° , Find ∠ X
 Sulotion:∠ M ≅ ∠ J ,∠ Y ≅ ∠ A ,∧¿
∠X ≅∠N

∠ X =70 °
E. Developing mastery (Lead Seatwork:Application
to Formative assessment)
Complete ME (Student answer may varied)
Michael is planning to create a triangular
window. He asks for a plan from his
colleague, but the plan is incomplete.
Your task is to help Michael complete
the missing information on the plan so he
can start cutting the steel for the window.
The figure below shows that ∆ JOY is
congruent to∆ FUL .Find the value of n
and ∠ L.

J L F
60 ° (2 n+10)°

70 °
O Y U
 We know that when ∆ JOY ≅ ∆ FUL the
corresponding angles ∠ U and ∠ O are
congruent, Thus, they have the same
measures.
∠ U =¿ ¿
2 n+10=¿ _____
2 n=¿ 70 _____
60
¿¿
2
n=¿ ¿

G. Finding practical Finding Distances (Localization)

applications of concepts
and skills in daily living. The map below shows your school
campus (LAEnHS). The distance Student 7: Sir 5 Miles sir,
between the canteen and library is similar
to the distance between the stage and CR.
However, the stage and canteen are also
similar in distance to the library.
Stage
6m
Canteen
C.R.

7m

Library
Using the information in the map, what is
the distance between Canteen to Stage
and Library to C.R.?

H. Making generalizations Abstraction:

and abstractions about the
lessons  Two angles are congruent if and only
if their vertices can paired so that
corresponding sides and
corresponding angles are congruent.
 Corresponding parts of congruent
triangles are congruent

I. Valuing Connect the Triangle to the Role of

Parent at home.
J. Evaluating learning Quiz:
 A. Fill in the blanks. (1 pt each)

Congruent triangles have the same

________ and ______. The vertices of
the congruent __________ can be
_______ so that their corresponding
_________ and ________ are ________.
In short, two triangle are __________ if
and only if their _________ and
_________ are congruent.

Choices:

Size Equal shape

Angles triangles sides

Matched angles congruent

Lenghth

B. Determine if the triangles are

congruent. Write the corresponding
congruent parts and write the statement
of congruence statement.

Corresponding Vertices:

Congruence Sides:

Congruence Angles:

F. Assignment: Assignment:
Advanced Study for the next topic
Type equation here .

Prepared by:

LEONARDO P. ALBOR
JIMWELL M. HABANA
Pre-Service Teacher Noted by:
LEAH P. OLARTE
Cooperating Teacher