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unit of measure: the base unit | the supplementary unit | the derived unit

geometry: the area of a flat figure | the area of a solid | the volume of the solid

The area of a ring

by its diameters


A ring is the area bounded by two concentric circumferences on a plane.

The area of a ring is the product of quarter of the value of π and the difference between the squares of the diameters of both large and small circles.

Computing relationship:


d1 — the outer diameter;

d1 — the inner diameter.

Calculator: the area of a ring by its diameters

For separation of number integers and decimals, use the symbol – point [.]

the outer diameter — d1

the inner diameter — d2


the area of a ring by its diameters =



context information: contemporary and archaic unit of measurement of area