Question

Area of rectangle whose length 15 cm is 120 sq cm.find the perimeter.

Answer 1

46cm

Area of Rectangle= Length×Breadth

120 sq= 15cm × x

120 sq= 15x

120/15= x

8cm= x

Breadth= 8cm

Perimeter of Rectangle= 2(Length+Breadth)

Perimeter of Rectangle= 2(Length+Breadth)

Perimeter of Rectangle= 2(15cm+8cm)

Perimeter of Rectangle= 2 × 23cm

Perimeter of Rectangle= 46cm

Perimeter of Rectangle= 46cm

Answer 2

Given :-

Length of the rectangle = 15 cm

Area of a rectangle = 120 cm²

To Find :-

The perimeter of a rectangle.

Analysis :-

Consider the breadth of the rectangle as a variable.

Substitute the values in the formula of area of rectangle and get the value of the variable.

Once you get the length and breadth, substitute them in the formula of perimeter of rectangle.

Solution :-

We know that,

• l = Length
• b = Breadth
• a = Area
• p = Perimeter

Let us consider the breadth to be 'x'.

By the formula,

$\underline{\boxed{\sf Area \ of \ rectangle=Length \times Breadth}}$

Given that,

Length (l) = 15 cm

Area (a) = 120 cm²

Substituting their values,

$\sf 120 = 15 \times x$

$\sf x=\dfrac{120}{15}$

$\sf x=8$

Therefore, the breadth of the rectangle is 8 cm.

By the formula,

$\underline{\boxed{\sf Perimeter \ of \ rectangle=2(Length+Breadth)}}$

Given that,

Length (l) = 15 cm

Breadth (b) = 8 cm

Substituting the values,

Perimeter = 2(15 + 8)

= 2(23)

= 46 cm

Therefore, the perimeter of the rectangle is 46 cm.