5 Views

Question : The perimeter of a rectangle is 68 cm. If the area of the rectangle is 240 cm2, then what is the length of each of its diagonals?

Option 1: 25 cm

Option 2: 27 cm

Option 3: 26 cm

Option 4: 28 cm


Team Careers360 5th Jan, 2024
Answer (1)
Team Careers360 11th Jan, 2024

Correct Answer: 26 cm


Solution : Given,
Perimeter of a rectangle = 68 cm
Area of the rectangle = 240 cm 2
Let the length be l and breadth be b.
Perimeter of Rectangle = 2(l + b)
⇒ 2(l + b) = 68
⇒ l + b = 34............(1)
Also, Area of rectangle = l × b
⇒ l × b = 240.............(2)
From (1), we get l = 34 – b,
⇒ (34 – b) × b = 240
⇒ b 2 – 34b + 240 = 0
⇒ b 2 – 10b – 24b + 240 = 0
⇒ b(b – 10) – 24(b – 10) = 0
⇒ (b – 24)(b – 10) = 0
⇒ b = 10 or 24
$\therefore$ Length, l = 24 or 10 cm
We know, Pythagoras's theorem: Perpendicular 2 = Length 2 + Breadth 2
⇒ Length of diagonal = $\sqrt{24^2+10^2}=\sqrt{576+100}=\sqrt{676}= 26\ \text{cm}$
Hence, the correct answer is 26 cm.

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
GRE ® Registrations 2024
Apply
Apply for GRE® Test now & save 10% with ApplyShop Gift Card | World's most used Admission Test for Graduate & Professional Schools
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books