# RD Sharma Solutions for Class 9 Maths Chapter 19: Surface Area and Volume of Cuboid and Cube

A cuboid is a solid structure made of 6 planes (faces), 12 edges and 8 vertices. In other words, it can be said that it is made up of 6 quadrilaterals. A cube is a cuboid with all equal edges. For example, we can take a brick as a perfect cuboid, and your Rubik's cube can be taken as a perfect example of a Cube. Some important parameters about Cuboid and Cube are necessary to be learnt in this chapter. These parameters include:

The surface area of any cuboid face is the area it occupies when placed on the floor. For example, a cuboid has rectangular planes. So, the surface area of a cuboid will be the area of quadrilateral, i.e., Length X Breadth. The total surface area of the cuboid is 6 X Length X Breadth. 6 is multiplied because a cuboid has 6 surfaces. But the cuboid doesn't have every length and breadth equal; thus, the formula becomes Total Surface Area= 2(lb + bh + lh)

The surface area of a face of a Cube can be determined by the formula (Length)2 square units. Hence the total surface area of a cuboid can be determined by 6 X (Length)2 square units

The volume of a cuboid is defined as the amount of matter that can be poured into it. The formula for the cuboid volume is Volume = Length x Breadth x Height or the area of a cross-section x height.

For a cube Volume = Length3 cubic units.

These formulas can solve real-life problems, such as how much water can be poured in a cuboid chamber or how much area will be taken by a brick while building a house, etc.