Geometry Cheat Sheet: Area & Volume
Whether you are painting a wall (Area) or filling a pool (Volume), knowing these formulas saves you time and money.
2D Area Formulas (Flat)
- Rectangle: Width x Height
- Triangle: (Base x Height) / 2
- Circle: π x Radius²
3D Volume Formulas (Solid)
- Cube/Box: Length x Width x Height
- Cylinder: (π x Radius²) x Height
- Sphere: (4/3) x π x Radius³
Real World Example: Painting a Room
A wall is 10ft wide and 8ft high.
Area = 10 x 8 = 80 sq ft.
If a gallon of paint covers 400 sq ft, one gallon can paint 5 of these walls.
Real World Example: Mulch for Garden
You want 3 inches (0.25 ft) of mulch in a garden bed that is 10ft x 4ft.
Volume = Length x Width x Depth
Volume = 10 x 4 x 0.25 = 10 cubic feet.