Page 2 - LN 2

Perimeter of a rectangle
The perimeter of a rectangle is the total length of all the sides of the rectangle.
Hence, we can find the perimeter by adding all four sides of a rectangle.

Perimeter of the given rectangle is a + b + a + b. Since opposite sides of a rectangle
are always equal, we need to find the dimensions of only two sides to find the
perimeter of a rectangle.
The perimeter of the above rectangle with sides ‘a units’ and ‘b units’ is:

a + b + a + b = 2a + 2b = 2 (a + b) units.
Hence, the formula for the perimeter of a rectangle = 2 × (sum of adjacent sides)

Example: Shabana wants to put a lace border all around a rectangular table-cover 3 m
long and 2 m wide. Calculate the length of the lace required by Shabana.

Solution: From the given information, length of the rectangular table-cover (l) = 3 m,
breadth of the rectangular table-cover (b) = 2 m.

Shabana’s requirement is to put a lace border all around the table-cover.

Therefore, the length of the lace will be equal to the perimeter of the rectangular table –
cover.

Now, perimeter of the rectangular table-cover = 2 × (length + breadth) = 2 × (l + b)