Question

1. The length of a rectangle is three times.its width. If the perimeter is 84m, find the length of the rectangle.​

Answer 1

Answer:

31.5m.

Step-by-step explanation:

Let the width be x.

Then, the length will be 3x.

Perimeter of rectangle = 2(l + w)

Substitute values

⟹ 84 = 2(3x + x)

⟹ 84 = 2(4x)

⟹ 8x = 84

⟹ x = 84/8

⟹ x = 21/2

⟹ x = 10.5.

Therefore,

Length of rectangle = 3x = 3(10.5)

= 31.5m.

Answer 2

✰ Given :

• The length of a rectangle is three times its width (breadth) . The perimeter of the rectangle is 84 m . We here are to find the length of the rectangle.

Solution :

• Let's assume the width of the rectangle as y .

• Let's assume the length of the rectangle as 3y .

We know that,

• Perimeter = 2( l + w)

Here,

• l denotes Length

• w denotes Width

✰ According to the Question :

$\\ \\ \tt \therefore \: \: \: \: \: \: \tt \: 2(3y + y) = 84 \: m \\ \\ \\ : \implies \tt2(4y) = 84 \: m \\ \\ \\ \tt : \implies \: 8y = 84 \: m \\ \\ \\ \tt : \implies \: y = \frac{84}{8} \: m \\ \\ \\ \: \: \: \: \tt : \implies y = {\underline{ \boxed{ \mathfrak{ \pmb{10.5\: m}}}}}$

Therefore,

• Length of the rectangle = 3y = 3 × 10.5 m = 31.5 m