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Area and Area and PerimeterPerimeter

of Irregular of Irregular BlocksBlocks

Stage 6 - Year 11Stage 6 - Year 11

Applied Mathematic(Preliminary General 1)

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If you are doing building, landscaping or some other activity you may need to find the perimeter or area of an irregular block of land.

Regular IrregularEnd ofSlide

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Surveyor’s Notebook.This is a diagrammatic representation.

Transverse

Irregular blockof land.

010m

12m 20m

25m

25m10m

10

35

50

12 20

5m20m

45

25

20

Surveyors Notebook.

End ofSlide

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0.5x20x5

0.5x10x12

Rectangle

T1 = = 60

T2 =0.5x10x20 = 100

T3 = = 50

T4 =0.5x15x25 = 187.5

TR =0.5x25x(25+12)= 465.5

RE =20x35 = 700

AreaTrap=0.5xhx(a+b)

Finding the Area

10m

12m 20m

25m

25m

10m

5m20m

End ofSlide

Triangle 1

T1

Triangle 2

T2

Triangle 3T3

Triangle 4

T4

Trapezium

TRRE

AreaTriangle=0.5xbxhAreaRectangle= LxBTotal Area =1563m2

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Finding the Perimeter

10m

12m 20m

25m

25m

10m

5m20m

End ofSlide

T1 T2

T3

T4

TRRE

T1: c12= 102+122=244c1≈15.6

T2: c22=102+202=500 c2≈22.4

T3: c32= 52+202=425 c3≈20.6

T4: c42=152+252=850 c4≈29.2

TR: cT2=132+252=794 c4≈28.2

13m

RE: cR2=35 c4≈35

Total =151 mc2 = a2 + b2

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Finding the AreaHouse

Press

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Finding the AreaWe want to concrete the driveway.If the concrete is 30cm thick thenhow much concrete do we need?

End ofSlide

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Finding the AreaDraw the line shown below.Divide in half,and half again.

End ofSlide

Simpson’s Rule:A ≈ h÷3(dfirst+4dmiddle+dlast)

h=6m

h=6m

df=0m

dm=3m

dL=2.5m

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End ofSlide

Simpson’s Rule:A ≈ h÷3(dfirst+4dmiddle+dlast)

h=6m

h=6m

df=0m

dm=3m

dL=2.5m

A ≈ 6÷3 x (0 + 4x3 + 2.5)

h=6m

h=6m

dF=2.5m

dm=2.8m

dL=0m+ 6÷3 x (2.5 + 4x2.8 + 0)≈ 56.4 m2

V ≈ 56.4 m2x .3 m

≈ 16.92 m3

≈ 17 m3