Page 87 - Mathematics_Std_4

Activity 1 Measuring the perimeter of a rectangle

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Width

Length

Steps

1. Put the 0 mark on a tape measure at one corner of the
rectangle.

2. Measure the length of the rectangle’s boundary until you
reach the starting point.

3. Record the measurement of the length obtained.

4. Measure and record the length of each side of the rectangle
using a ruler.

5. Add the lengths of all sides of the rectangle in step 4.

6. Compare the results from step 3 with those from step 5.

7. What is the perimeter of the rectangle.

In Activity 1, the total length of the boundaries obtained is the
perimeter of the rectangle. Thus, the perimeter of a rectangle is

obtained by adding the lengths of all its four sides

The formula for finding the perimeter of a rectangle is given by;
Perimeter of a rectangle = length + width + length + width
= length + length + width + width

= 2 × length + 2 × width
Therefore, the perimeter of a rectangle = 2 × length + 2 × width.

=
If =l length and w width, then the perimeter will be;
The perimeter of a rectangle = ×+2 l 2 × w

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06/11/2024 17:17:16
MATHEMATICS STD 4 PB 2024.indd 80
MATHEMATICS STD 4 PB 2024.indd 80 06/11/2024 17:17:16