Session 29: Perimeter word problems Session Title Perimeter word problems  Objective By the end of this lesson, students will be able to: Define perimeter and understand its significance. Calculate the perimeter of various shapes, including squares, rectangles, and irregular polygons. Apply perimeter concepts to real-life situations. Concepts Whiteboard and markers Ruler or measuring tape Chart with formulas for perimeter Worksheet with practice problems Geometry tools (optionals) Materials required  A measuring tape or ruler Paper and pencil Classroom objects (benches, desks, windows, doors, etc.) Methodology  Direct Instruction: The Teacher introduces the concept of perimeter with examples and uses diagrams. Hands-on Practice: Students work on exercises individually or in pairs to calculate the perimeter of different shapes. Session Duration  90 minutes  Introduction activity (10 minutes): Engage students: Ask, “What do you think ‘perimeter’ means?” Hook Question: “If you walked all the way around your backyard, what are you measuring?” (Introduce the idea of perimeter.) Define Perimeter: The distance around a 2D shape. Show visuals of different shapes and identify their sides. Main Activity (70 minutes): Teach formulas: (10 minutes) Rectangle: P = 2(l + w) Square: P = 4 × side Triangle: P = a + b + c Use real-life examples: (15 minutes) 1. Fencing a garden Problem: Rectangle Garden  Sarah wants to put a fence around her rectangular garden. The length of the garden is 8 meters and the width is 5 meters. Question: What is the total length of fencing Sarah needs? Answer: Perimeter = 2 × (Length + Width) = 2 × (8 + 5) = 2 × 13 = 26 meters  2. Square Chalkboard Problem: A chalkboard in the classroom is square and each side measures 5 feet. Question: What is the total length of trim needed to go around the board? Answer:  Perimeter = 4 × 5 = 20 feet 3 Triangle Question: A triangle has sides that measure 6 cm, 7 cm, and 5 cm. What is the perimeter? Solution:  Perimeter = 6 + 7 + 5 = 18 cm   Independent Practices (25 minutes) Rectangle Problem A rectangle has a length of 8 cm and a width of 5 cm. What is its perimeter? Solution: Perimeter = 2 × (length + width) = 2 × (8 + 5) = 2 × 13 = 26 cm Square Problem Each side of a square is 9 meters. What is the perimeter of the square? Solution: Perimeter = 4 × side = 4 × 9 = 36 meters Square Tile One square floor tile has sides that measure 30 cm. Question: What is the perimeter of the tile? Solution:  Perimeter = 4 × 30 = 120 cm Triangle Problem A triangle has sides that measure 6 cm, 7 cm, and 5 cm. What is the perimeter? Solution: Perimeter = 6 + 7 + 5 = 18 cm Triangular Flower Bed A triangular flower bed has three sides that measure 7 feet, 9 feet, and 6 feet. Question: What is the total length of the fencing needed for the flower bed? Solution: Perimeter = 7 + 9 + 6 = 22 feet Irregular Shape Problem A shape has sides measuring 3 cm, 4 cm, 5 cm, 2 cm, and 6 cm. What is the total perimeter? Solution: Perimeter = 3 + 4 + 5 + 2 + 6 = 20 cm Missing Side Problem A rectangle has a length of 14 m. The perimeter is 46 m. What is the width? Solution: Perimeter = 2 × (length + width) 46 = 2 × (14 + width) 46 = 28 + 2 × width 46 - 28 = 18 2 × width = 18 → width = 9 meters   Game Time  (20 minutes) Instruction: Ask the children what they see in the farmhouse. Give them only the questions you have given them, and explain the questions in a way that will lead them to the answer. These problems should be divided into 4 papers and given to each group. Divide them into four groups and give the same topics to two groups.. Group 1 - farm house Group 2 - classroom Group 3- farm house  Group 4- classroom  Farmhouse related problems  1. Fencing or Walls Problem: You want to fence the entire perimeter of your farmhouse which is 100m long and 60m wide. Question: How much fencing is needed? Solution: Perimeter = 2 × (100 + 60) = 320 മീറ്റർസ് 2. Gates Problem: You plan to install a gate on each side of a square farmhouse (each side 75 meters). Question: What is the distance between each gate if equally spaced? Solution: Perimeter = 4 × 75 = 300 meters Distance between gates = 300 ÷ 4 = 75 meters 3. Paths or Roads Problem: A walking path is to be laid around the edge of the farmhouse (perimeter = 280 meters). Question: If it costs ₹50 per meter to build the path, what is the total cost? Solution: 280 × 50 = ₹14,000 4. Animal Pens or Shelters Problem: You plan to build 3 animal pens along one 90-meter side of the perimeter, spaced equally. Question: How long is each pen (if no space between)? Solution: 90 ÷ 3 = 30 meters per pen 5. Hedges or Trees Problem: You are planting trees every 10 meters along a 240-meter perimeter. Question: How many trees do you need? Solution: 240 ÷ 10 = 24 trees 6. Water Channels or Ditches Problem: You want to dig a drainage ditch along the full perimeter (300 meters). Question: How much digging is required? Solution: 300 meters of ditch Classroom related problems  1. Walls Problem: The classroom is rectangular, with a length of 8 meters and a width of 6 meters. Question: What is the perimeter of the classroom? Solution: Perimeter = 2 × (8 + 6) = 2 × 14 = 28 meters 2. Doors Problem: There are 2 doors in the classroom, each measuring 1.5 meters wide. If the total perimeter of the classroom is 28 meters. Question: What is the total width of the doors compared to the perimeter? Solution: Total width of doors = 2 × 1.5 = 3 meters. The doors take up 3 meters of the perimeter. 3. Windows Problem: There are 4 windows, each 2 meters wide, placed along the perimeter of the classroom. Question: What is the total width of all the windows? Solution: Total width of windows = 4 × 2 = 8 meters 4. Blackboard/Whiteboard Problem: The classroom has a whiteboard that is 3 meters wide. If you want to place a frame around the whiteboard, Question: What is the perimeter of the frame? Solution: Perimeter = 2 × (3 + 1) = 2 × 4 = 8 meters (assuming a 1-meter height for the whiteboard). 5. Decorations or Charts Problem: You plan to hang charts along 3 walls, with each wall being 5 meters long. Question: What is the total length of the walls where charts will be hung? Solution: Total length = 3 × 5 = 15 meter The team that completes the problems first will win Review Questions (5 minutes): Follow up Task (5 minutes): Home Work Rectangle Garden: Lena is planting a rectangular garden that is 9 meters long and 6 meters wide. Question: How much fencing will she need to go around the garden? Answer: Perimeter = 2 × (9 + 6) = 2 × 15 = 30 meters Expected Learning Outcome  Knowledge building Formulas for Perimeter Definition of Perimeter Properties of Shapes Skill building Reading and Understanding Word Problems Calculation Accuracy Choosing the Right Formula