Question

Sujata will draw a rectangular picture on a paper with area 84sq cm. The difference of length and breath of paper is 5 cm. Let us calculate the perimeter of paper of sujata.

Answer 1

area of rectangle= length × width

84= l×w

l-w= 5

84= 12×7

5=12-7

perimeter of rectangle=2l+2w

p=(2×12)+(2×7)

p=24+14

p=38

use correct unit for each one.

Answer 2

Step-by-step explanation:

Let length be L, breadth be B.

We know, area of rectangle = length × breadth

Given, Area of rectangular picture = 84 cm2

⇒ L × B = 84cm2

Also, Given the difference of length and breadth is 5 cm.

⇒ L - B = 5cm

Or L = B + 5

Substituting, (B + 5) × B = 84

B2 + 5B - 84 = 0

B2 + 12B - 7B - 84 = 0

B(B + 12) - 7(B + 12) = 0

(B - 7)(B + 12) = 0

B cannot be negative, so B = 7cm.

L = 12cm

Perimeter of a rectangle = 2(L + B)

= 2(12 + 5) = 34cm