Perimeter of square

Let’s take a square

We know that

In a square, all sides are equal

  AB = BC = CD = AD

Let AB = a

So,

     AB = BC = CD = AD = a

Now,

  Perimeter of square = Sum of all sides

    = AB + BC + CD + AD

    = a + a + a + a

   = 4a

   = 4 × Side of square

So,

        Perimeter of square = 4a

          = 4 × Side of square

Let’s solve some examples

Find perimeter of a square whose side is 15 cm

Given,

  Side of square = a = 15 cm

So,

  Perimeter of square = 4 × side of square

    = 4a

    = 4 × 15

    = 60 cm

Thus, Perimeter of square is 60 cm

Find perimeter of a square whose side is 0.5 m

Given,

  Side of square = a = 0.5 m

   = 0.5 × 100 cm  (1m = 100 cm)

   = 50 cm

So, Perimeter of square = 4 × Side of square

= 4a

= 4 × 50

= 200 cm

= 200/100 m         (1 cm =  1/100 m )

= 2 m