The length of a rectangle is twice it's width. If it's perimeter is 54cm, find its length. Explain!

Let width=x cm

so, Length=2x cm

Perimeter of rectangle=2(length+width)

54=2(x+2x)

54=6x

x=9 cm

Length of rectangle=2*9=18 cm

 

 

 

Solution -   

Let width of the rectangle   =x cm

so, Length of the rectangle

 =2x cm

Perimeter of rectangle=2(length+width)

54=2(x+2x)

54=6x

x=9 cm

Length of rectangle=2*9=18 cm

 

Let width be w cm. So, length of rectangle =  2w cm.

Perimeter   = w+w+2w+2w  = 6w 

6w  = 54 

w  = 54/6 = 9 cm  length = 2w  = 18 cm 

width=x cm , Length=2x cm , Perimeter=54cm ,,, P=2L+2W --> 54=2x+2(2x) =2x+4x --> 54=6x .. ..Divide both sides by 6 to get the value of x(width). --> 54/6=6x/6 --> x=9 cm .. the width is 9 cm. Length of rectangle is twice the width= 2*9 .. The length is 18 cm.

Let width be x cm. So, length of rectangle will become 2x cm.

Now, perimeter of rectangle  = 2(length + width) = 2(x + 2x) = 6x cm

So, Perimeter = 6x = 54cm => x = 9cm.

Hence, length = 2x = 18 cm