ppt

1. OBJECTIVES :
Illustrate the ASA Congruence Postulate.
Relate the idea of congruence in real life.
Indicate the additional corresponding parts
needed to make the triangles congruent by
using ASA congruence postulate.
1.

2. What is the symbol of congruence
, its meaning ?
Congruence means having the same shape
and size, it denoted by ≅. The top part of
the symbol, ∿, is the sign for similarity and
indicates the same shape. The bottom part,
=, is the sign of equality and indicates the
same size.

3. Can you see how the idea of
congruence is used in the mass
production of various products ?
 Congruence is very important in mass production and
manufacturing. Parts must be identical or congruent, to be
interchangeable. For example , in the assembly line of
motorcycle/ bicycle/ other vehicles or TV sets , gadgets, the
same part needs to fit into each unit that comes down the
assembly line.
 Having congruent parts available in the market also allows for
easier repair and maintenance of the products.
 The idea of congruence is all around us. Consider ( a ) the paper
bills in our wallet are congruent, ( b ) the coins of the same
denomination, ( c ) any two spoons or forks in a set of silverware
are congruent, ( d ) a duplicate key is congruent to the original
key, ( e ) CD”s.

4.  In your G7 Math , what is a triangle ?
 In previous lesson , when can we say that the
triangles are congruent ?
 In your English subject : use the word triangle to
form a sentence.
 In History , what famous landmark which you can
compare in a triangle shape ?

5. TOPIC : ASA Congruence Postulate
Specific Criteria
Comprehensive
And Detailed
( 5 points )
Partially
complete, lacks
detail
(4 points )
Incomplete, few
details
(3 points )
Insufficient or
Inaccurate ( 2
points )
score
Accuracy of the
measures
Completeness of
the figure
Correctness of
Data
TOTAL

6. ACTIVITY : TRY MORE ( 8-10 minutes )
ASA (Angle-Side Angle) Congruence
 Prepare the following materials; pencil, ruler, protractor, a
pair of scissors , construction paper, bond paper. Working
independently, use a ruler and a protractor to draw ΔBOY
with two angles and the included side having the following
measures: m∠B = 50degrees, m∠O = 70 degrees and BO =18
cm
 1. Draw BO measuring 18 cm in a construction paper.
 2. With B as vertex draw angle B measuring 50 degrees,
 3. With O as vertex draw angle O measuring 70 degrees,
 4. Name the intersection as Y.
 5. Cut out the triangle and compare it with four of your
classmates.

7. ANALYSIS : ( 3-5 mins. )
What is an included side?
Can we easily determine the
included sides given the two angles
even without a figure ?
How can we determine the
included side given the two angles?

8. BY PAIR :
 a. Describe the triangles which you compare.
 b. Put identical marks on the congruent corresponding
sides and angles.
 c. Identify the parts of the triangles which are given
congruent. Why those are the corresponding
congruent parts ?

9. ABSTRACTION : 1 MINUTE
When can we say that the
two triangles are
congruent by ASA
Congruence ?

10. ASA (Angle-Side-Angle)
Congruence Postulate
If the two angles and the
included side of one triangle are
congruent to the corresponding
two angles and an included side
of another triangle, then the
triangles are congruent by ASA
CONGRUENCE.

11. APPLICATION :Work by group, use activity
sheet ( 4-5 minutes )
 GROUP 1
 A. Corresponding congruent parts are marked.
Indicate the additional corresponding parts needed to
make the triangles congruent by using the ASA
congruence postulate


12. GROUP 1
B. Refer to the figure above. The two triangles are congruent
by ASA Congruence Postulate. State whether the statement
is true or false.
 1. BCA ≅ EFD
2. ABC ≅ DEF
3. CBA ≅ FED

13. GROUP 2
 If ∠A ≅ ∠E, JA ≅ ME, ∠J ≅ ∠M,
then ΔJAY ≅ ΔMEL
 Draw the triangles and mark the congruent
parts.

14. GROUP 3
 MAN ≅ BOY. Complete each statement.
 A ≅ ____ 2. BY ≅ ______ 3. m N ≅ _____
 POT ≅ BIN
 4. Is TOP ≅ NIB ? Explain.
 5. Is PTO ≅ INB ? Explain.

15. EVALUATION : ( 5 minutes )
 Use activity sheet.
 Corresponding congruent parts are marked. Indicate
the additional corresponding parts needed to make
the triangles congruent by using the ASA congruence
postulate. Five points each correct answer.

16. HOMEDELIGHT
 In your big notebook. Copy and answer.
 A cellular phone company makes congruent
rectangular batteries for different kinds of
cellular phone model.
 @ Does it make sense to produce congruent
batteries for different models of cellular phones ?
Why ?