The sum of the length, breadth and depth of a cuboid is

Home » Aptitude » Volume and Surface Area of Solid Figures » Question

The sum of the length, breadth and depth of a cuboid is 19 cm and its diagonal is 5√5 cm, its surface area is ?

1. 361 cm²
2. 125 cm²
3. 236 cm²
4. None of these

Correct Option: C

Let x, y and z be the length breadth and deapth of a cuboid.
∴ x + y + z = 19
x² + y² + z² = (5√5)² = 125
Surface area of the cuboid = 2(xy + yz + zx)
= (x + y + z)²) - (x² + y² + z²)
= 361 - 125 = 236 cm³