Step1: Start the class by asking a question like- If i have to build a fence around a garden which is square shape then how will I know how much wire do I need? What do you suggest should I be doing?
In the meanwhile to make the students visualize the garden, draw a square on the blackboard and label it as the garden.
Step 2: Students will say we can measure the length of the garden. That’s when you probe- what do you mean by length? Is it the boundary of the sides of the garden or is it the diagonals (which you can draw as a dotted line on the blackboard for the square) .In case students are unable to understand, then ask your question again- you want to build a fence around (emphasis the word around with actions) the garden, how will you know the wire length required for it.
Someone from the students will be able to guess the answer . You need to look for the key words like “measure the boundary of the garden”. This when you introduce the word Perimeter.
Step 3: Explain the words- Peri +meter
PERI= around something
Meter= is the unit to measure
Once you have explained them Peri meter- then begin measuring the sides of the square garden on the blackboard using the scale.
Give names to the sides and start writing the measurements. Then add up all the sides.
Activity- Give children4-5 strips of paper 16cms length and ask them to make two shapes out of them by cutting the strips equally. One triangle and one rectangle. Once they have done that ask them to measure the same . Ask them to recreate the same in their notebooks and write their measurements. And perimeter for each figure.
- Find the perimeter of the rectangle shown below.