Geometry
Ellipse Perimeter (approx)
Ramanujan's approximation of ellipse perimeter.
Formula
Formula
P ≈ π[3(a+b) − √(3a+b)(a+3b)]
Variables
| Symbol | Definition | Type & range | Units | Role |
|---|---|---|---|---|
| a, b | semi-axes | real number (ℝ) | — | input |
Try it yourself
Interactive calculator
Worked examples
Example 1
Givensemi-axis a = 5, semi-axis b = 3
Result25.52698639
Example 2
Givensemi-axis a = 4, semi-axis b = 4
Result25.13274123