Question

A painting is done on a cardboard 12 cm long and 9 cm wide such that there is a margin of 2 cm along each of its sides. find the area of the margin ​

Answer 1

GIVEN

A cardboard of dimension 12cm × 9cm

Margin around cardboard of 2cm is applied.

TO FIND

The area of the margin

SOLUTION

From the given Question we can conclude that there are 2 rectangles one smaller one (inside margin line) and larger one (including margin line).

Now, the the dimension of given rectangle is 12cm and 9cm while the margin of smallar rectangle is

(12 - 2 - 2)cm and (9 - 2 - 2)cm

i.e. 8cm and 5cm

Hence the area lf the border is

ar.Large rectangle - ar.Smalle rectangle

= (12 × 9) - (8 × 5)

= 108 - 40

= 68cm^2

Applying formula :-

area(rectangle) = Length × Breadth

Hence area of border is 68 cm^2 (ANS)

Answer 2

ANSWER:-

Given:

A painting is done on a cardboard 12cm long and 9cm wide such that there is a margin of 2cm along each of its sides.

To find:

The area of the margin.

Explanation:

We have,

• Length of the cardboard= 12cm
• Breadth of the cardboard= 9cm

We know that formula of the area of rectangle : Length × Breadth

So,

Area of original cardboard= [12×9]cm²

Area of original cardboard= 108cm²

&

• There is 2cm left all around the cardboard.

Length of the new cardboard:

⇒ Length of the original cardboard- 2 × 2

⇒ 12cm - 4cm

⇒ 8cm

Breadth of the new cardboard:

⇒ Breadth of the original cardboard - 2 × 2

⇒ 9cm - 4cm

⇒ 5cm

Area of the new cardboard=[8 × 5]cm²

Area of the new cardboard= 40cm²

Now,

• Area of the margin

⇒ Area of the original cardboard - Area of the new cardboard

⇒ 108cm² - 40cm²

⇒ 68cm²

Thus,

The area of the margin is 68cm²