### Teorija

Lai salīdzinātu lielus un mazus, šaurus un platus ķermeņus, lieto laukuma vienības.
Starptautiskajā vienību sistēmā laukuma pamatvienība ir kvadrātmetrs  $\left({m}^{2}\right)$.

Iegaumē, kā jārīkojas, lai pārietu no vienām vienībām uz citām!
$\begin{array}{l}1\phantom{\rule{0.147em}{0ex}}{\mathrm{km}}^{2}=1000\phantom{\rule{0.147em}{0ex}}m\cdot 1000\phantom{\rule{0.147em}{0ex}}m\phantom{\rule{0.147em}{0ex}}=1\phantom{\rule{0.147em}{0ex}}000\phantom{\rule{0.147em}{0ex}}000\phantom{\rule{0.147em}{0ex}}{m}^{2}\\ 1\phantom{\rule{0.147em}{0ex}}{\mathrm{cm}}^{2}=\phantom{\rule{0.147em}{0ex}}0,01\phantom{\rule{0.147em}{0ex}}m\cdot 0,01\phantom{\rule{0.147em}{0ex}}m\phantom{\rule{0.147em}{0ex}}=0,0001\phantom{\rule{0.147em}{0ex}}{m}^{2}\\ 1\phantom{\rule{0.147em}{0ex}}{\mathrm{dm}}^{2}=0,1\phantom{\rule{0.147em}{0ex}}m\phantom{\rule{0.147em}{0ex}}\cdot 0,1\phantom{\rule{0.147em}{0ex}}m\phantom{\rule{0.147em}{0ex}}=0,01\phantom{\rule{0.147em}{0ex}}{m}^{2}\\ 1\phantom{\rule{0.147em}{0ex}}{\mathrm{mm}}^{2}=0,001\phantom{\rule{0.147em}{0ex}}m\cdot 0,001\phantom{\rule{0.147em}{0ex}}m\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}0,000001\phantom{\rule{0.147em}{0ex}}{m}^{2}\end{array}$

$\begin{array}{l}1\phantom{\rule{0.147em}{0ex}}{\mathrm{m}}^{2}\phantom{\rule{0.147em}{0ex}}=1000\phantom{\rule{0.147em}{0ex}}\mathrm{mm}\phantom{\rule{0.147em}{0ex}}\cdot 1000\phantom{\rule{0.147em}{0ex}}\mathrm{mm}\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}1\phantom{\rule{0.147em}{0ex}}000\phantom{\rule{0.147em}{0ex}}000\phantom{\rule{0.147em}{0ex}}{\mathrm{mm}}^{2}\\ 1\phantom{\rule{0.147em}{0ex}}{\mathrm{m}}^{2}=\phantom{\rule{0.147em}{0ex}}100\phantom{\rule{0.147em}{0ex}}\mathrm{cm}\cdot 100\phantom{\rule{0.147em}{0ex}}\mathrm{cm}\phantom{\rule{0.147em}{0ex}}=10\phantom{\rule{0.147em}{0ex}}000\phantom{\rule{0.147em}{0ex}}{\mathrm{cm}}^{2}\\ 1\phantom{\rule{0.147em}{0ex}}{\mathrm{m}}^{2}=\phantom{\rule{0.147em}{0ex}}10\phantom{\rule{0.147em}{0ex}}\mathrm{dm}\cdot 10\phantom{\rule{0.147em}{0ex}}\mathrm{dm}\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}100\phantom{\rule{0.147em}{0ex}}{\mathrm{dm}}^{2}\\ 1\phantom{\rule{0.147em}{0ex}}{\mathrm{m}}^{2}=\phantom{\rule{0.147em}{0ex}}0,001\phantom{\rule{0.147em}{0ex}}\mathrm{km}\phantom{\rule{0.147em}{0ex}}\cdot 0,001\phantom{\rule{0.147em}{0ex}}\mathrm{km}\phantom{\rule{0.147em}{0ex}}=\phantom{\rule{0.147em}{0ex}}0,000001\phantom{\rule{0.147em}{0ex}}{\mathrm{km}}^{2}\end{array}$

Sadzīvē izmanto laukuma mēru  - hektāru [ha].
$1\phantom{\rule{0.147em}{0ex}}\mathrm{ha}\phantom{\rule{0.147em}{0ex}}=10000\phantom{\rule{0.147em}{0ex}}{m}^{2}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}\phantom{\rule{0.147em}{0ex}}1\phantom{\rule{0.147em}{0ex}}{m}^{2}=0,0001\phantom{\rule{0.147em}{0ex}}\mathrm{ha}$

Lai noteiktu ķermeņa laukumu, izmanto šādas formulas.
Taisnstūra laukums ir $\phantom{\rule{0.147em}{0ex}}\mathit{garums}\cdot \mathit{platums}\phantom{\rule{0.147em}{0ex}}$.
Garumu fizikā pieņemts apzīmēt ar burtu l, laukumu ar S. Tādā gadījumā taisnstūra laukums $S\phantom{\rule{0.147em}{0ex}}={l}_{1}\cdot {l}_{2}$
Trijstūra laukums $S=\frac{\mathit{ah}}{2}$, kur a ir mala, bet h ir pret šo malu vilktais augstums.
Riņķa laukums $S=\mathrm{\pi }{R}^{2}\phantom{\rule{0.147em}{0ex}}\left(\mathrm{\pi }\approx 3,14\right)$, kur R - riņķa rādiuss.