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- 1. Lesson 51:Identifying and Describing Triangles MARVIE T.BLANCO FOUR-KINDNESS URDANETA I CENTRAL SCHOOL URDANETA CITY,PANGASINAN
- 2. Objective : Identify and describe triangles according to sides and angles.
- 3. Value focus : patriotism
- 4. 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 corners .
- 5. 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.
- 6. 3.Motivation: 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?
- 7. B . Developmental Activities 1.Presentation 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 . Triangular flaglet Observe the different triangular objects . How will you describe the different triangular objects?
- 8. 2.Performing the Activities [team work] Classify the following cutouts into 2 groups and describe them according to their sides and angles.
- 9. 3.Processing the Activities[observe the different triangles] Do all triangles have equal sides? Do they all have equal angles DISCUSSION 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.
- 10. 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 than 90˚. 3) An obtuse triangle has an obtuse angle which measures more than 90.˚
- 11. 4.Reinforcing the Concept and Skill Discuss the presentation under Explore and discover on page 162 of the LM.
- 12. 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 sides. 2]Does an acute triangle have an obtuse angle. 3]Does an equilateral triangle have equal sides.
- 13. 4]Does an scalene triangle have no equal sides. 5]Does a right triangle have a right angle. 6]Does an obtuse triangle have an acute angle?
- 14. C . Keep Moving !page 163 of LM Answer the following questions. 1.How many equal sides does an isosceles triangle have. 2.How many equal sides does an equilateral triangle have? 3.What kind of angle does an acute triangle
- 15. 5.Generalization: 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.
- 16. 6.Applying to New and other Situations. A]Choose the correct answer. Write your answer in your notebook.[right triangle ,acute triangle, scalene triangle, obtuse 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 congruent sides Is ______________. 6.A triangle that has more than 90º angles is
- 17. Do “Apply Your Skills” on page 163 Using old calendars, cut out triangles. Classify them according to sides and angles.
- 18. C. Assessment Name the triangle described in each item. 1.It is a triangle which has a right angle. 2.It is a triangle which has an obtuse angle. 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.
- 19. 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
- 20. Enrichment : DAY 1 Draw the following figures with the indicated measurement: 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. 4.Right triangle 5.Obtuse triangle,110˚ 6.Acute triangle, 70˚
- 21. ENRICHMENT DAY 2 Draw the following triangles. 1.Equilateral triangle 2.Acute triangle 3.Scalene triangle 4.Right triangle 5.Isosceles triangle 6.Obtuse triangle
- 22. ENRICHMENT :DAY 3
- 23. ENRICHMENT :DAY 4
- 24. THANK YOU SO MUCH ! MARVIE T.BLANCO FOUR-KINDNESS URDANETA I CENTRAL SCHOOL URDANETA CITY,PANGASINAN