Question

find the area of rec. whose length is twice the breadth and perimeter is 30​

Answer 1

Answer:

72

Explanation:

let the breadth be x

So,length is 2x

So, perimeter= 2(l+b)

=2(2x+x)

=2(3x)

=5x

but perimeter=30

5x=30

so,x=30/5

=6

So,length =2x =2×6=12

and breadth=x= 6

Now,area =l×b

=6×12 =72

Answer 2

Question :

Find the area of rec. whose length is twice the breadth and perimeter is 30cm

Answer:

Given:

• Length of rectangle = 2x
• Breadth of rectangle = x

To find:

• The area of rectangle

Solution:

Before, finding the area we need to find the actual value of length and breadth of rectangle .

So, Let us take the breadth = x

Length of rectangle = 2x ㅤㅤ(given)

ㅤ

Perimeter of rectangle = 2(l + b)

ㅤ$:\implies$ 30 = 2 ( 2x + x )

ㅤ$: \implies$30 = 4x + 2x

ㅤ$: \implies$ 30 = 6x

ㅤ$: \implies$ x = 5

ㅤ

Breadth of rectangle = x = 5cm

So, length of rectangle = 2x = 5(2) = 10cm

ㅤ

Area of rectangle = length × breadth

ㅤ$: \implies$ 10 × 5

ㅤ$: \implies$ 50cm²

ㅤ

Therefore, the area of rectangle = 50cm²