Answer :

The area of the rectangle is 54 square cm or 54 cm².

Given that: Length of the rectangle is 3 cm longer than its width. The perimeter of a rectangle is 30cm. To find the area of the rectangle.

What is a rectangle?

A rectangle is a closed figure which is a parallelogram whose length of the opposite sides is equal and the angle between each of its edges is a right angle or it is a right-angled parallelogram whose length of the opposite sides is equal.

Let the length of the rectangle be l and the breadth of the rectangle be b.

As per the question: length is 3 cm longer than width.

Therefore, the length of the rectangle = b + 3

Length of the rectangle = b + 3

Width of the rectangle = b

The formula for the perimeter of a rectangle is given:

P = 2 × (l + b). where

l = length of the rectangle

b = breadth of the rectangle

P = perimeter

given perimeter in the question P = 30 cm

Putting values of l, b, and P in the equation.

30 = 2 × ((b + 3) + b)

=> 30 = 2 × (b + 3 + b)

Dividing both sides by 2:

30 / 2 = 2 × (b + 3 + b) / 2

=> 15 = 2b + 3

or 2b + 3 = 15

Subtracting both sides by 3:

2b + 3 - 3 = 15 - 3

2b = 12

Dividing both sides by 2:

2b / 2 = 12 / 2

b = 6

The width of the rectangle is b = 6 cm

The length of the rectangle is (6 + 3) cm, l = 9 cm

Therefore, the width is 6 cm and the length is 9 cm.

The area of the rectangle is given by the formula:

A = l × b where,

A = area

l = length of the rectangle

b = breath of the rectangle

Putting values of l and b in the equation, we get:

A = 9 × 6

= 54

Therefore, the area of the rectangle is 54 square cm or 54 cm²

Hence the area of the rectangle is 54 square cm or 54 cm².

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