1.1
1.2
Measuring instruments
1.4
Imperial Units(in. yd. ft. mi.)
Referent
Abbreviation
Unit analysis
SI system measures(We are going to talk about it later.)
Proportional reasoning
Convert measurements between SI units and imperial units
SI units
1.4
Right pyramid
Apex
Slant height
Polygon base
Lateral area
Right cone
1.5
Cylinder
Right prism
Base area
Cone
Radius
1.6
1.7
Sphere
Surface area
Volume
Hemisphere
Substitute
Composite Objects
•
•
Review how to:
Convert the units
Imperial units with Imperial units——Jack
Imperial units with SI units——Ikaros
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•
•
•
•
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Calculate the surface area of 3-D shapes——Yoyo
Right Cone
Right Pyramid
Right Prism
Right Cylinder
Sphere
Hemisphere
Calculate the volumes of 3-D shapes(above-mentioned)——Yoyo
Solving Problems Involving Objects——Apple
Example Questions
Quiz Time!10-15minutes/7 questions(multiple-choice)No written!
Imperial
Unit
Abbrevia tion inch foot yard mile in.
ft.
yd.
mi.
Referent Relations hip between
Units
Thumb length
Foot length
1ft.=12in.
Arm span 1yd.=36in
.=3ft.
Distance walked in
20 min
1mi.=
1760yd.=
5280ft.
SI UNIT
Millimetre(mm)
Centimetre(cm)
Metre(m)
Kilometre(km)
IMPERIAL UNIT
Inch(in)
Foot(ft)
Yard(yd)
Mile(mi)
SI Units
1km=1000m
1m=100cm
1cm=10mm
1m=1000mm
1m=10dm
Imperial Units
1mi=1760yd
=5280ft
=63360 in
1yd=3ft=36in
1ft=12in
1in=0.083333ft
1ft=0.3333yd
SI Units to
Imperial Units
1mm ≈ 0.04in
Imperial Units to
SI units
1in=2.54cm
1cm≈0.4in
1m≈39in
1m≈3.25ft
1km≈0.6mi
1ft≈30cm
1ft≈0.3m
1yd=91.44cm
1yd≈0.9m
1mi≈1.6km
A lane is approximately
19m long.
What is this measurement to the nearest foot?
(1m≈3.25 ft.)
From the table,1m≈3.25 ft.
So,19m≈19 x (3.25) ft.
19m≈62 ft.
A length of 19m is approximately 62 ft.
Convert 6 ft. 2 in. to inches
1 ft. = 12 in.
So, 6 ft. = 6
12 in.
6 ft. = 72 in
And, 6 ft. 2 in.=72 in. + 2 in. =74 in.
A truck driver knows that his truck
is 3.5m high.The support beams of a bridge are 11ft.9in. high. Can the truck cross the bridge smoothly?
(1cm≈0.4in)
h truck
=3.5m=350cm
350cm × 0.4 in.=137.8 in
h bridge
=11ft.9in=141in > 137.8in
h bridge
> h truck
Yes! It can~
Area is the twodimensional (2-D) size of a surface.
Surface area (SA) of a solid is the total area of
the exposed surfaces of a three-dimensional (3-D) object.
Right Cone
A
Side
= πrs
A
Base
= πr 2
SA = πr 2 + πrs
Square-based Pyramid
A triangle
= ½ bs
A base
= b 2
SA = 2bs + b 2
General Right Pyramid
SA = sum of all the areas of all the faces
~Pyramid head~
Rectangular Prism
SA = 2( hl + lw + hw )
Right Cylinder
A top
=πr 2
A bottom
=πr 2
A side
=2πrh
SA=2πr 2 + 2πrh
1. Which expression could be used to calculate the surface area of the right square-based pyramid with a base length of 10 cm and a
height of 12 cm?
*
SA = 2bs + b 2
2. Raj was asked to make a cylindrical tank with a lateral surface area of 2622 m 2 and a height of 23 m.
Which net diagram below would be correct for this cylinder?
*Lateral SA= A side
=2π rh
2πrh=114 × 23=2622
is the space that a shape occupies often quantified numerically using the SI unit , the cubic meter .
Right Cone
A
Base
= πr 2
V=1/3(area of base)h
=1/3πr 2 h
General Right Pyramid
V = 1/3(area of base) h
Square-based Pyramid
V = 1/3b 2 h
Right Rectangular Pyramid
V = 1/3lwh
~Pyramid head~
General Right Prism
V=(area of base)h
Rectangular Right Prism
V=lwh General Right Prism
Rectangular Prism
Right Cylinder
A base
=πr 2
V=(area of base)h
=πr 2 h
3. Which of the following expressions represents the volume of the cylinder below?
(*
V cylinder = πr 2 h
)
d=2x+4
So, r=1x+2
V= πr 2 h=π(1x+2) 2 (3x-1 )
……
It’s “C”!
Definition of sphere:
A sphere is the set of points which are all the same distance from a fixed point which is the centre in space. A line segment that joins the centre to any point on the sphere is a radius. A
and passes through the centre is a diameter.
Surface Area of a Sphere
π
2
Surface Area of a Hemisphere
2
The diameter of a baseball is approximately 3 in. Determine the surface area of a baseball to the nearest square inch.
Solution:
Use the formula for the surface area of a sphere.
The radius is:
½(3 in.) = 1.5 in.
SA = 4 π r2
SA = 4 π (1.5)2
SA= 28.8
The surface area of a baseball is approximately 28 square inches.
V =4/3πr
3
The sun approximates a sphere with diameter 870 000 mi. What is the approximate volume of the sun?
Use the formula for the volume of a sphere.
The radius, r, is: r = ½ (870 000mi.) r = 435 000mi.
V = 4/3 πr 3
V = 4/3 π(435 000mi.) 3
V = 3.4479 * 10 17
Determine the volume of this composite object to the nearest tenth of a cubic meter.
First
The object comprises a right rectangular prism and a right rectangular pyramid.
Use the formula for the volume of a right rectangular prism.
V= lwh
V=(6.7)(2.9)(2.9)
V= 56.347
Then
Use the formula for the volume of a right rectangular pyramid.
V= 1/3 lwh
V= 1/3(6.7)(2.9)(2.1)
V= 13.601
Volume of the composite object is:
56.347 + 13.601= 69.948
The
So, the volume of the composite object is approximately 69.9 m3.
Let’s have a xiao quiz~