Annulus

Annulus formulas

Notations

r : inner circle radius
R : outer circle radius
w : annulus width
c : inner circle circumference
C : outer circle circumference
a : inner circle area
A : outer circle area
AA : annulus area

Annulus width

`w=R-r`

Circumferences

`c=2*pi*r`

`C=2*pi*R`

Areas

`a=pi*r^2`

`A=pi*R^2`

`\text{AA}=pi*(R^2 - r^2)`

See also

Plane Geometry calculators
Geometry calculators
Mathematics calculators