Facts that Matter
SOLIDS AND THEIR SURFACE AREAS
The bodies occupying space are called solids, such as a cuboid, a cube, a cylinder, a cone, a sphere, etc. These solids have plane or curved surfaces.
SURFACE AREA OF A CUBOID AND A CUBE
The outer surface of a cuboid is made up of six rectangles. If we take the length of the cuboid as ℓ, breadth as b and the height as h, then Surface area of a cuboid = 2[lb + bh + hl]
Let us recall that a cuboid whose length, breadth and height are equal is called a cube. Let each edge of the cube be ‘a’, then Surface area of a cube = 6a2
I. Sometimes a cuboid does not have bottom and top faces. In such cases the area of four facesis called the lateral surface area.
II. Lateral surface area of a cuboid is 2(ℓ + b)h.
III. Lateral surface area of a cube is 4a2.
IV. Surface area of a cuboid or cube means total surface area.