What is the CSA (Curved Surface Area) of a Cube?

Technically, a cube does not have any 'curves'. Therefore, mathematicians prefer to use the term Lateral Surface Area (LSA) instead of Curved Surface Area. However, in many school textbooks and exams, both terms are used interchangeably to mean the exact same thing.

The formula is extremely easy to understand if you break the cube apart:

1. A cube has a total of 6 identical square faces.
2. The area of just one square face is side × side = a².
3. The CSA (or Lateral Surface Area) specifically asks for the area of only the 4 side walls, completely ignoring the top roof and the bottom floor.
4. Since you are only adding the areas of the 4 side walls, the formula is simply a² + a² + a² + a² = 4a².

Question: A wooden cube has an edge length of 5 cm. If you want to paint only its four side walls, what is the total area to be painted?

Solution:

• We are given the side length: a = 5 cm.
• Since we are painting only the 4 walls, we need the CSA.
• Formula: CSA = 4a²
• CSA = 4 × (5)²
• CSA = 4 × 25
• CSA = 100 cm². (Therefore, 100 square centimeters need to be painted).