Question
Download Solution PDFThe sum of the length, width and depth of a cuboid is 8 cm and its diagonal is 5 cm. What is its surface area?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
Length + Width + Height = 8 cm
Diagonal = 5 cm
Formula used:
Diagonal2 = l2 + w2 + h2
Surface Area = 2 × (lw + wh + hl)
Calculation:
Let l + w + h = 8 ...(i)
⇒ Diagonal2 = 52 = 25
⇒ l2 + w2 + h2 = 25 ...(ii)
Now, (l + w + h)2 = l2 + w2 + h2 + 2(lw + wh + hl)
⇒ 82 = 25 + 2(lw + wh + hl)
⇒ 64 = 25 + 2(lw + wh + hl)
⇒ 2(lw + wh + hl) = 39
⇒ lw + wh + hl = 19.5
Surface Area = 2 × 19.5 = 39 cm2
∴ The surface area is 39 cm².
Last updated on Jun 2, 2025
-> The Railway Recruitment Board has released the RPF Constable 2025 Response Sheet on 24th March 2025. As per the official notice, the RPF Constable Answer Key will be available from 24th March 2025 to 29th March 2025.
-> The RRB ALP 2025 Notification has been released on the official website.
-> The Examination was held from 2nd March to 18th March 2025. Check the RPF Exam Analysis Live Updates Here.
-> RPF Constable 2025 application status was released in January 20, 2025.