Aptitude - Area - Discussion

Discussion Forum : Area - General Questions (Q.No. 9)
9.
The diagonal of a rectangle is 41 cm and its area is 20 sq. cm. The perimeter of the rectangle must be:
9 cm
18 cm
20 cm
41 cm
Answer: Option
Explanation:

l2 + b2 = 41.

Also, lb = 20.

(l + b)2 = (l2 + b2) + 2lb = 41 + 40 = 81

(l + b) = 9.

Perimeter = 2(l + b) = 18 cm.

Discussion:
15 comments Page 2 of 2.

Hrishi said:   9 years ago
You explained very well @Vinit Kumar.
(1)

Silmn said:   8 years ago
Why (a + b)^2 formula is used here?
(1)

Abhi said:   1 decade ago
How did you took root of 41 there?

Mmmm said:   1 decade ago
How did you take 40 there ?

Krish said:   1 decade ago
How 81 came?


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