Semi-detailed Lesson Plan in math IV (k-12 based curriculum) "FINDING THE AREA OF A TRIANGLE"
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This lesson plan aims to teach students how to find the area of a triangle. It reviews prerequisite concepts like finding the area of parallelograms. Example problems are used to introduce and explain the formula for calculating the area of a triangle: A = 1/2 * base * height. Students are divided into groups to practice applying the formula by solving example triangle area problems and finding missing side lengths. The lesson concludes by having students complete a table practicing various triangle area calculation problems.
Semi-detailed Lesson Plan in math IV (k-12 based curriculum) "FINDING THE AREA OF A TRIANGLE"
- 1. Semi-detailedLessonPlaninMathematicsIV I. OBJECTIVE Findthe area of a triangle. II.PREREQUISITE CONCEPTSANDSKILLS a. Topic:Findingthe Areaof a Triangle b. References:MathematicsIV Learner’sGuide,pages205-208, MathematicsForLife 4, pages 225-226, Internet c. Materials:BigParty Hat, Coloredpapers,Ruler,activitysheets forgroupings,laptopand projector d. Values:Perseveranceand cooperation III.INSTRUCTIONALPROCEDURE A. PreliminaryActivities 1. SPAD Yaya Dub needstocleanthe garden.The garden isinparallelogramshaped.If the basedis 12 metersandthe heightis6 meters.Finditsarea. 2. Drill Solve the followingnumbersentencesusingmultiplicationanddivision. 1. 8 x 4 ÷ 2 = n 2. (5)(8) 2 3. 12 x 3 2 4. 10 x 5 ÷ 2 = n 5. 3 x 4 ÷ 2 = n 3. Review Findthe area of each parallelogram. = n = n b = 6m h = 4m b = 3cm h = 8cm
- 2. B. DevelopmentalActivities 1. Motivation Ask: - What isthe shape of the hat Billywantsforhiscostume? - Measure the base and the heightof the hat. What isthe height?Whatisthe base? 2. Presentation Vocabularywords: AREA - a part or sectionwithinalargerplace. TRIANGLE – a shape thatmade up of 3 lines,3 anglesand3 sides. FINDINGTHE AREA OF A TRIANGLE So,the area infindingthe areaof a triangle isA = 𝑏ℎ 2 or A= 1 2 (bh) , where b= base andh = height. Examples: Billywantstobuy a triangularhatfor hiscostume.He goesin a supermarketandthere he findssomanyhats. HelpBillytofindthe hat he wantsfor hiscostume. b= 6cm h = 6cm If we have twotrianglesandtheycombined together.We formedaparallelogram, thus, triangle ishalf of a parallelogram. The area in findinga parallelogramisA = bh 3cm A = bh/2 A = 6cm x 3cm / 2 A = 1 sq cm 2. A = bh/2 A = 8m (3m)/2 A = 12 sqm
- 3. 1. 3. Application - Divide the classinto4. Group 1: Draw a righttriangle.Label the base andheightas12 cm and4 cm. Findthe area. Group 2: Vince issurveyingaplotof landinthe shape of triangle.The areaof the land is24 square meters.If the heightmeasured4meters.Whatisthe base? Group 3: A 10 metersladderisleaningagainstthe building.The bottomof the ladderis 5 metersawayfrombuilding.Whatisthe area of the space of the ladder? Group 4: whatisthe heightof a triangle withabase of 5 inchesandan area of 20 square inches? 4. Generalization The formulainfindinganarea of a triangle isA = bh/2or A = ½ bh where b= base and h = height. The formulainfindingthe missingheightandbase of a triangle is: b = A(2)/handh = A(2)/b IV.EVALUATION Solve the following. 1. Ss V.HOME ACTIVITY Complete the table below. Triangle Base (b) Height (h) Area 1 4 m 2 m 2 6 cm 4 cm 3 12 in 84 sq in 4 12 m 36 sq m 5 9 dm 10 dm 6cm 8m 3m h = 4m b = 6m A =? A = 3 sq m b = 2m h =? 2. 3. h = 5cm A = 10 sqcm b =?