Volume vs Surface Area
Volume measures the space inside a 3D shape — reported in cubic units (cm³, m³). Surface area is the total area of all faces on the outside — reported in square units (cm², m²).
Think of volume as how much water fits in a box, and surface area as how much paper you'd need to wrap it.
Key Formulas
Rectangular Prism: V = l × w × h | SA = 2(lw + lh + wh)
Cylinder: V = πr²h | SA = 2πr² + 2πrh (two circles + rectangle wrapped around)
Pyramid (square base): V = ⅓ × base area × height
For irregular shapes, use the principle: Volume = Base Area × Height (or ⅓ of that for cones and pyramids).