Chapter 14: Surface Area and Volume (Cube-Cuboid)

Surface Area and Volume (Cube-Cuboid) closes the Class 8 syllabus by calculating total surface area, lateral surface area, and volume for cubes and cuboids — including combined, real-world objects like boxes, rooms and tanks. A cuboid measuring 4m×3m×2m has a volume of 24 cubic metres, but a total surface area of 2(4×3+3×2+4×2)=52 square metres — two genuinely different numbers from the same three measurements.

Confusing total surface area (all six faces) with lateral surface area (only the four side faces) is the single most common mistake here. This chapter is also the direct starting point for Class 9's Surface Areas and Volumes, which extends the same ideas to cylinders, cones and spheres.