# S2: Area and Volume:

Usually in the topic of shape we use two types of measurement, Imperial and Metric.
However in this topic we are going to focus on the metric units.
Here are some measuement of area:
• square millimetres (mm²)
• square centimetres (cm²)
• square metres (m²)
• hectares (ha) =10000m²
• square kilometres (km²)
In area, you may need to convert to other measures, you do this like so

• If: m→km = ×1000
• Then: m²→km² = ×1000² or 1000000
• So: 1000000m² = 1km²

Here are some metric measures of volume:
• cubed millimetres (mm³)
• cubed centimetres (cm³)
• cubed metres (m³)
• cubed kilometres (km³)

This is how to find volumes of certain 3 dimentional shapes:

Cube:
Volume:
$\fn_cm \bg_white \300dpi \inline x^{3}$
Surface Area:
$\fn_cm \bg_white \300dpi \inline 6x^{2}$
Cuboid:
Volume:
$\fn_cm \bg_white \300dpi \inline lwh$
Surface Area:
$\fn_cm \bg_white \300dpi \inline 2(l(h+w)+hw)$
###### The circle
A circle is a shape with both infinite lines of symmetry and one side set in one curve. These are all similar shapes and their circumference:diameter are all the same. this is commonly known as pi.
The sign for pi is $\fn_cm \bg_white \300dpi \inline \pi$ and is an irrational number, this means it cannot be expressed as $\fn_cm \bg_white \300dpi \inline \frac{x}{y}$:

You may not need to know this but$\fn_cm \bg_white \300dpi \inline \pi$ to 1000 places is:

3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 8214808651 3282306647 0938446095 5058223172 5359408128 4811174502 8410270193 8521105559 6446229489 5493038196 4428810975 6659334461 2847564823 3786783165 2712019091 4564856692 3460348610 4543266482 1339360726 0249141273 7245870066 0631558817 4881520920 9628292540 9171536436 7892590360 0113305305 4882046652 1384146951 9415116094 3305727036 5759591953 0921861173 8193261179 3105118548 0744623799 6274956735 1885752724 8912279381 8301194912 9833673362 4406566430 8602139494 6395224737 1907021798 6094370277 0539217176 2931767523 8467481846 7669405132 0005681271 4526356082 7785771342 7577896091 7363717872 1468440901 2249534301 4654958537 1050792279 6892589235 4201995611 2129021960 8640344181 5981362977 4771309960 5187072113 4999999837 2978049951 0597317328 1609631859 5024459455 3469083026 4252230825 3344685035 2619311881 7101000313 7838752886 5875332083 8142061717 7669147303 5982534904 2875546873 1159562863 8823537875 9375195778 1857780532 1712268066 1300192787 6611195909 216420198

$\fn_cm \bg_white \300dpi \inline \pi=\frac{circumference}{diameter}$ ←here stands a key statement
﻿
﻿Here are some circle facts:
﻿Area:
$\fn_cm \bg_white \300dpi \inline \pi r^{2}$
Perimeter:
$\fn_cm \bg_white \300dpi \inline 2\pi r^{2}$
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﻿
﻿
﻿A.Centre
﻿B.Diameter
﻿C.Circumference
﻿D.Arc
﻿E.Chord