Review-10B Measurement - TangHua2012-2013

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Measurement

10B Apple Yoyo Jack Ikaros

Content

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

 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

(1ft=12in)

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

What is it ???

and passes through the centre is a diameter.

Surface Area of a Sphere

The surface area, SA, of a sphere with radius r is :

SA = 4

π

r

2

Surface Area of a Hemisphere

The surface area, SA, of a hemisphere with radius r is :

SA=3πr

2

Here is the example:

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.

Volume of a Sphere

The volume, V, of a sphere with radius r is :

V =4/3πr

3

Example:

The sun approximates a sphere with diameter 870 000 mi. What is the approximate volume of the sun?

Solution:

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

1.7 Solving Problems

Involving Objects

Example:

Determine the volume of this composite object to the nearest tenth of a cubic meter.

Solution:

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.

That’s all in the chapter 1

Easy Right?

So, that’s all we need to teach you today.

NO MORE Q?

Let’s have a xiao quiz~

Remember to…

Choose “C”!

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