Home › Formulas › Geometry
Geometry Formulas
Area, perimeter, volume, and surface area for every common shape and solid.
2D shapes — area & perimeter
| Triangle | A = ½·b·h | P = a + b + c |
| Heron's formula | A = √(s(s−a)(s−b)(s−c)) | s = (a+b+c)/2 |
| Right triangle | a² + b² = c² | Pythagoras; c = hypotenuse |
| Rectangle | A = l·w | P = 2(l + w) |
| Square | A = s² | P = 4s |
| Parallelogram | A = b·h | P = 2(a + b) |
| Trapezoid | A = ½·(a + b)·h | a,b = the two bases |
| Circle | A = πr² | C = 2πr |
| Ellipse | A = π·a·b | a,b = semi-axes |
| Sector | A = ½·r²·θ | θ in radians; arc = rθ |
3D solids — volume & surface area
| Cube | V = s³ | SA = 6s² |
| Rectangular prism | V = l·w·h | SA = 2(lw + lh + wh) |
| Cylinder | V = πr²h | SA = 2πr² + 2πrh |
| Cone | V = ⅓·πr²h | SA = πr² + πrs (s = slant height) |
| Sphere | V = ⁴⁄₃·πr³ | SA = 4πr² |
| Pyramid | V = ⅓·B·h | B = base area |