Question

When you multiply the length 3times of rectangle without altering it's breadth how many you multiply the area

Answer 1

Answer:

area of rectangle = l x b

if length = 3l

and breadth remain same ..

new area = 3 times the old one

A' = 3A

Step-by-step explanation:

Answer 2

Answer:

Correct option is B)

Let the breadth of the rectangle be x cm.

Then, length = 3x cm

New breadth =(x+5) cm

New length =(3x−3)cm

Then, (x+5)(3x−3)−3x×x=57

⇒3x

2

+12x−15−3x

2

=57

⇒12x=57+15=72⇒x=6

∴ Breadth = 6 cm, Length = 18 cm

Perimeter =2(6cm+18cm)=2×24cm=48 cm