Class 9 | Chapter 13 | Surface areas and Volumes | Exercise 13.1 | Question 3

Question 3: The floor of a rectangular hall has a perimeter 250 m. If the cost of painting the four walls at the rate of Rs. 10 per m2 is Rs. 15000, find the height of the hall.

[Hint : Area of the four walls = Lateral surface area.]

Prerequisite

Finding surface area of a cube or a cuboid is quite simple. Every cube/cuboid has 6 sides. All we need is find the area of all six sides and add – this will be the total surface area of the cube/cuboid.

A cube is a cuboid that has all edges of equal length. Hence, every cube is a cuboid as well but every cuboid is not a cube. 

It is recommended to understand the core concept of area, surface area and volume before we attempt any question based on these concepts.

 
Derivation of formula – Surface area of cube and cuboid
 

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