Question

5. The length of a room is y metres. Write the
breadth of the room which is 20 m less than
twice the length. Write an expression for the
perimeter of the room.​

Answer 1

ANSWER

Let the breadth of the rectangle is b cm.

So, the length of the rectangle is 2b cm.

We know that the perimeter of rectangle is

=2(l+b)

Since, perimeter of rectangle is 120 cm.

Therefore,

6b=120

b=20 cm

And l=40 cm

So, the area of rectangle is

=20×40=800 cm2

Hence, the length is 40 cm, breadth is 20 cm and area is 800 cm2.

Answer 2

Step-by-step explanation:

Length of the room=y metre

Breadth of the room=(2y-20) metres

Perimeter of the room=2 (L+B)

=2(y+2y-20)

This is the answer dear