Chapter Name: Learning how to measure
Activity Name: Measuring the area of a regular surface in Learning how to measure
The experiment involves measuring the area of a regular surface, specifically a rectangle. A cardboard with dimensions 4 cm by 2 cm is cut into the shape of a rectangle.
The area of the cardboard will be measured using a centimetre graph paper, where each small square has a side length of 1 cm.
- Centimetre graph paper
- Sharp pencil
Step by Step Procedure:
- Cut a cardboard into a rectangle shape with a length of 4 cm and a breadth of 2 cm.
- Take a centimetre graph paper, where each small square has a side length of 1 cm.
- Place the cardboard on the centimetre graph paper and outline its shape using a sharp pencil.
- Remove the cardboard and mark the outlined shape as PQRS.
- Count the number of squares inside the outline. In this case, the number of squares is 8.
- The area of the cardboard is equal to the area covered by PQRS on the graph paper.
- Calculate the area of PQRS by multiplying the number of squares (8) by the area of 1 unit square (1 cm^2). Area of PQRS = 8 × 1 cm^2 = 8 cm^2
- The cardboard was cut into a rectangle shape with dimensions 4 cm by 2 cm.
- The outlined shape PQRS on the graph paper contained 8 small squares.
- The area of the cardboard, measured as the area covered by PQRS, was found to be 8 cm^2.
- Handle the sharp pencil carefully to avoid any accidents.
- Ensure the cardboard is accurately cut into the specified dimensions.
- Place the cardboard carefully on the graph paper to accurately outline its shape.
Lesson Learnt from Experiment:
The measured area of the cardboard (8 cm^2) can be related to the formula for finding the area of a rectangle. In general, the area of a rectangle is calculated by multiplying its length by its breadth or width.
In this experiment, the length of the rectangle was 4 cm and the breadth was 2 cm, which gives an area of 8 cm^2. Therefore, the formula for finding the area of a rectangle (length × breadth) can be applied to determine the measured area in this experiment.