Rectangle area
Geometry
How to calculate annulus area
This tool calculates annulus area from Outer radius, Inner radius. Enter each quantity in its labelled field, then use the formula below to check the calculation.
Formula
π × (outer radius² − inner radius²)
Worked example
- Outer radius
- 5
- Inner radius
- 3
Applying the formula to these values gives 50.2654824574 square units.
What should I check?
Find the area, perimeter, surface area or volume of common shapes. Use consistent length units: metres produce square metres for areas and cubic metres for volumes.
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