පෘෂ්ඨ වර්ගඵලය සහ පරිමාව — සා/පෙළ ගණිතය

How much paint covers a cylindrical water tank? How many litres does that tank hold? How much steel goes into a length of pipe? These are not textbook puzzles — they are the everyday sums of builders, engineers and shopkeepers all over Sri Lanka. Surface area answers "how much material to cover it?" and volume answers "how much fits inside it?". In this lesson you learn to compute both for the two solids that show up most in the O/L paper: the cylinder and the triangular prism.