Definition:Imperial/Area

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Definition

The imperial units of area are based on a system of units in which each unit is the square of a corresponding imperial length unit.

The imperial units of area are as follows:


Square Inch

One square inch is equal to a square of side $1$ inch in length.

\(\ds \) \(\) \(\ds 1\) square inch
\(\ds \) \(=\) \(\ds 6 \cdotp 4516 = 2 \cdotp 54^2\) square centimetres

The definition is exact.


Square Foot

One square foot is equal to a square of side $1$ foot in length.

\(\ds \) \(\) \(\ds 1\) square foot
\(\ds \) \(=\) \(\ds 144 = 12^2\) square inches


Square Yard

One square yard is equal to a square of side $1$ yard in length.

\(\ds \) \(\) \(\ds 1\) square yard
\(\ds \) \(=\) \(\ds 9 = 3^2\) square feet
\(\ds \) \(=\) \(\ds 1296 = 36^2\) square inches


Square Rod, Pole or Perch

One square rod, pole or perch is equal to a square of side $1$ rod, pole or perch in length.

\(\ds \) \(\) \(\ds 1\) square rod, pole or perch
\(\ds \) \(=\) \(\ds 30 \dfrac 1 4 = \paren {5 \dfrac 1 2}^2\) square yards
\(\ds \) \(=\) \(\ds 272 \dfrac 1 4 = \paren {16 \dfrac 1 2}^2\) square feet


Square Chain

One square chain is equal to a square of side $1$ chain in length.

\(\ds \) \(\) \(\ds 1\) square chain
\(\ds \) \(=\) \(\ds 16 = 4^2\) square rods, poles or perches
\(\ds \) \(=\) \(\ds 484 = 22^2\) square yards


Rood

One rood is equal to an oblong measuring $1$ chain by $2 \frac 1 2$ chains.


\(\ds \) \(\) \(\ds 1\) rood
\(\ds \) \(=\) \(\ds 2 \tfrac 1 2\) square chains
\(\ds \) \(=\) \(\ds 40\) square rods, poles or perches
\(\ds \) \(=\) \(\ds 1210\) square yards
\(\ds \) \(=\) \(\ds 10 \, 890\) square feet
Rood.png


Acre

One acre is equal to an oblong measuring $1$ chain by $1$ furlong.

That is, measuring $4$ rods, poles or perches by $10$ chains.


\(\ds \) \(\) \(\ds 1\) acre
\(\ds \) \(=\) \(\ds 4\) roods
\(\ds \) \(=\) \(\ds 10\) square chains
\(\ds \) \(=\) \(\ds 160 = 4 \times 40\) square rods, poles or perches
\(\ds \) \(=\) \(\ds 4840 = 22 \times 220\) square yards
Acre.png


Square Mile

One square mile is equal to a square whose side measures $1$ mile.

\(\ds \) \(\) \(\ds 1\) square mile
\(\ds \) \(=\) \(\ds 640\) acres