A . Preliminary Activities
1.Drill[answer in the whiteboard]
Draw the polygon or lines described.
A)A plane figure with 3 sides and 3 angles.
B)A plane figure with 4 sides and 4 angles.
C)Lines that do not meet.
D)Lines that cross each other.
E)Lines that intersect and form square
2.Review:1]What is a triangle?
A triangle is a plane figure with 3 sides and 3 angles.
2]What is a quadrilateral?
A quadrilateral is a plane figure with 4 sides and 4 angles.
Ask : What can you see in the flag?
What plane figure can you see?
How do we show respect to the Phil. Flag?
What are the ways to show patriotism or
loyalty to our country?
B . Developmental Activities
Miss Fina assigned some of her pupils to
bring different objects with the shape of a
triangle . Benilda brought a picture of a house ,
Grace showed a picture of a road sign , and
Jocelyn prepared a triangular flaglet .
Observe the different
triangular objects . How will
you describe the different
2.Performing the Activities [team work]
Classify the following cutouts into 2 groups
and describe them according to their sides
3.Processing the Activities[observe the different
Do all triangles have equal sides? Do
they all have equal angles
Triangles can be classified according to sides.
A) An equilateral triangle has 3 equal sides.
B). An isosceles triangle has 2 equal sides.
C). A scalene triangle has no equal sides.
Triangles can be classified according
to their angles.
1) A right triangle has a right
angle which measures 90˚.
2) An acute triangle has 3
acute angles , each measuring less
3) An obtuse triangle has an
obtuse angle which measures more
4.Reinforcing the Concept and Skill
Discuss the presentation under Explore and
discover on page 162 of the LM.
B. Answer the following questions.
Draw a circle if your answer is Yes or a
diamond if it is no.
1]Does an isosceles triangle have 2 equal
2]Does an acute triangle have an obtuse
3]Does an equilateral triangle have equal
4]Does an scalene triangle have no equal
5]Does a right triangle have a right angle.
6]Does an obtuse triangle have an acute
C . Keep Moving !page 163 of LM
Answer the following questions.
1.How many equal sides does an
2.How many equal sides does an
3.What kind of angle does an
How are triangles classified ?
Triangles can be classified according to
angles as right , acute, or obtuse triangle . It
can also be classified according to sides as
equilateral, scalene, or isosceles triangle.
6.Applying to New and other Situations.
A]Choose the correct answer. Write your answer in
your notebook.[right triangle ,acute triangle, scalene
triangle , isosceles triangle or equilateral triangle]
1.A triangle which measures 90º is ______________.
2.A triangle which has no congruent angles is
3.A triangle which has 90º angle is ________________.
4.A triangle with three congruent angles of the same
measurement is ______________.
5.A triangle with two congruent angles and two
6.A triangle that has more than 90º angles is
Do “Apply Your Skills” on page 163
Using old calendars, cut out triangles.
according to sides and angles.
Name the triangle described in each
1.It is a triangle which has a right angle.
2.It is a triangle which has an obtuse
3.It is a triangle which has 3 acute angles.
4.It is a triangle which has 3 acute angles.
5.It is a triangle which has no equal sides.
6.It is a triangle which has 3 equal sides.
D . Home Activity [Remediation]
Draw the following triangles correctly.
1. Right triangle 4.Equilateral triangle
2.Obtuse triangle 5.Isoscles triangle
3.Acute triangle 6.Scalene triangle
Enrichment : DAY 1
Draw the following figures with the indicated
1.Equilateral triangle , each side measures 5 cm.
2.Isosceles triangle , equal sides measure 4cm each,
one side measures 6 cm.
3.Scalene triangle , side A measures 6cm, side B
measures 7cm,side C measures 4cm.
6.Acute triangle, 70˚
ENRICHMENT DAY 2
Draw the following triangles.