LESSON 5 · Math You Actually Use
Area Hides a Scaling Trap
A room that is 20% larger in every dimension is 44% larger in floor area — because area scales with the square of length. Triple every side and area grows 9×. This square-law is why a 20-foot room dwarfs a 15-foot one: the area ratio is 400/225 ≈ 1.78×, even though length only grew by a third.
The same logic traps homeowners. Paint costs scale with wall area, not length; flooring scales with floor area; heating and cooling scale with volume — taller ceilings cost more than people expect. Dimensions mislead; areas and volumes tell the financial truth.