Question

the width of a rectangle is two third of its length and the length exceeds the width by 7cm. Find its perimeter​

Answer 1

Answer :

The required perimeter of the rectangle = 70 cm

Step-by-step explanation :

Given :

• the width of a rectangle is two third of its length
• the length exceeds the width by 7 cm

To find :

the perimeter of the rectangle

Solution :

Let the length of the rectangle be L cm and the width of the rectangle be B cm

➣ The width of a rectangle is two third of its length

  $\sf B=\dfrac{2}{3}L \longrightarrow(1)$

➣ The length exceeds the width by 7 cm

  L = (B + 7) cm

Substitute L = B + 7 in (1)

  B = 2(B + 7)/3

  3B = 2(B + 7)

 3B = 2B + 14

 3B - 2B = 14

   B = 14

The width of the rectangle is 14 cm

Substitute the value of width in L = (B + 7)

L = 14 + 7

L = 21 cm

The length of the rectangle is 21 cm

We have to find the perimeter of the rectangle.

➙ Perimeter of the rectangle = 2(length + width)

➙ Perimeter of the rectangle = 2(L + B)

➙ Perimeter of the rectangle = 2(21 + 14)

➙ Perimeter of the rectangle = 2(35)

➙ Perimeter of the rectangle = 70 cm