Transcript Slide 1

Perimeter
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Units of length
Perimeters
Area Counting squares
Area Rectangle
Composite Areas
Area of Triangle
Carpet Problem
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Q1.
Solve the equation below
Q2.
Find two numbers that multiply to give 18
and subtract to give 3.
Q3.
Explain why the average of the numbers below is 7
2x  16  28
2,8,8,10
Q4.
21-Jul-15
True or false 60% of £240 = £144
Created by Mr. Lafferty Maths Dept.
Units of Length
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Learning Intention
1
We are learning the 4
metric units of length.
Success Criteria
1. Remember the 4 units of
length.
2. Be able to convert
between them.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Units of Length
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
The 4 units of length are :
The metre : This is the standard unit of length and is
approximately the distance from your nose
th
100
to the end of your outstretched arm.
1
100
The centimetre :
This is
of a metre and is about
the width of your pinky nail.
The Millimetre :
1000
This is 10 of a centimetre and is
about the width of a sewing needle.
The Kilometre :
21-Jul-15
1
This is 1000 metres and is about the
length of 10 football pitches.
Created by Mr. Lafferty Maths Dept.
Units of Length
Converting Measurements
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
×1000
Kilometres
(km)
×100
metres
(m)
1000
100
centimetres
(cm)
10
21-Jul-15
Created by Mr. Lafferty Maths Dept.
×10
millimetres
(mm)
Units of Length
Converting Measurements
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Examples
Convert 2m to cm :
2 x 100 = 200 cm
Convert 4km to m :
4 x 1000 = 4000 m
Convert 34cm to mm : 34 x 10 = 340 mm
Convert 50cm to m :
21-Jul-15
50 ÷ 100 = 0.5 m
Created by Mr. Lafferty Maths Dept.
Units of Length
Converting Measurements
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Now try Exercise 1
Ch10 (page 118)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
1.
True or false 2.3  8 = 184
2.
Convert metres (m)
(a) 200 cm
(b) 550 cm
(c) 50 cm
3
3. Show that
of 320 = 240
4
4.
21-Jul-15
Find 2 numbers that add to give 7
and multiply to give 10.
Created by Mr. Lafferty Maths Dept.
Perimeter
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Learning Intention
1. We are learning the term
perimeter of a shape.
Success Criteria
1. Understand the term
perimeter of a shape.
2. Calculate the perimeter of
a shape.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Perimeter
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
What is perimeter ?
Hint
answer is on the screen !
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Perimeter
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
21-Jul-15
Perimeter
Created by Mr. Lafferty Maths Dept.
Perimeter
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Perimeter
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Perimeter
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Perimeter
is the distance round the
outside of a 2D shape
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Perimeter
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
6cm
3cm
Calculate the
perimeter of the
rectangle below.
Demo
Perimeter =
6 + 3 + 6 + 3 = 18cm
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Perimeter
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Problem
xm
8m
Below is a drawing of the school
building. Calculate the perimeter.
4m
12 m
21-Jul-15
x = 12 – 9 =3 m
4m
9m
Perimeter
= 12 + 8 + 3 + 4 + 9 + 4
Created by Mr. Lafferty Maths Dept.
= 40 m
Perimeter
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Now try Exercise 2
Ch10 (page 121)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
MNU 2-11b
MNU2-11c
MTH 3-11b
Starter Questions
www.mathsrevision.com
Q1.
Solve the equation below
x  21  32
a
o
Q2.
Find the missing angles
Q3.
Find the average of the numbers below
2,5,6,7
Q4.
Which is the better deal
75% of £240
21-Jul-15
or
Created by Mr. Lafferty Maths Dept.
o
b
50% of £362
Area Counting Squares
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Learning Intention
1
We are learning the term
area.
Success Criteria
1. To understand the term
area.
2. Find the area by counting
squares.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Area Counting Squares
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
The area of a shape is simply defined by :
“the amount of space a shape takes up.”
Think of a square measuring 1 cm by 1cm we say it is :
1cm
1cm
21-Jul-15
1cm2
( 1 square centimetre )
Created by Mr. Lafferty Maths Dept.
Area Counting Squares
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Now try Exercise 3
Ch10 (page 123)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Q1.
What is the time difference 09:28 and 11:55
Q2.
Explain why the solution to the 3x  21  9
equation is x = 10
Q3.
Convert 23metres to
(a) cm
(b)
mm
Q4.
The answer to the question is 180.
What is the question.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Area of a Rectangle
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Learning Intention
1. Develop a formula for the
area of a rectangle.
Success Criteria
1. Remember area formula
for a rectangle.
2. Apply formula correctly.
(showing working)
3. Answer containing
appropriate units
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Area of a Rectangle
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
1 cm
B
B
L
L
L = length
L
B = Breadth
L
21-Jul-15
B
A
3
X
1
=
3
4
X
3
=
12
3
X
2
=
6
B
Area = length x breadth
A= L x B
Must learn formula !
Created by Mr. Lafferty Maths Dept.
Area of a Rectangle
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Example
Find the area of the rectangle opposite
B = 2cm
L = 9cm
Area = Length x Breadth
A=LxB
A=9x2
2
A = 18 cm
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Demo
Area of a Rectangle
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Example
Find the breadth B of the rectangle opposite
B cm
A = 36cm
L = 12cm
Area = Length x Breadth
A=LxB
36 = 12 x B
B=
36
12
Remember
units
B = 3cm
21-Jul-15
Balancing
Method
Created by Mr. Lafferty Maths Dept.
2
Area of a Rectangle
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Now try Exercise 4
Ch10 (page 125)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Now find the area of your
Measure the length of one
composite shape.
desk and round answer to
How many different ways
the nearest ten.
can you find the area.
Using an appropriate
Now find the perimeter
scale make a scale
of your shape.
drawing of your shape.
C of E Task
The desks in your group
have been arranged in a certain way
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
1
33 % of £270 = 90
3
Q1.
Why is
Q2.
What is the time difference 07:54 and 13:36
Q3.
Solve
Q4.
Convert 45.1 metres to
(a) cm
(b)
mm
Q5.
The answer to the question is 90.
What is the question.
21-Jul-15
5x  37  8
Created by Mr. Lafferty Maths Dept.
Area of a Composite
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Learning Intention
Made up of
Simple shapes
1. We are learning to find
area for more complicated
shapes.
Success Criteria
1. Use knowledge gained so
far to find the area of
more complicated shapes..
2. Show appropriate working.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Area of a Composite
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Calculate the area of this shape
9cm
Total Area = 72 + 30
= 102cm2
A=lxb
8cm
A=9x8
A=
6cm
A=lxb
72cm2
5cmA
=6x5
A = 30cm2
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Area of a Composite
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Calculate the area of this shape
8cm
10cm
6cm
21-Jul-15
12cm
Area of a Composite
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Calculate the area of this shape
Total Area = 80 + 24
= 104cm2
A=lxb
10cm
A = 8 x 10
A=lxb
A = 80cm2
A=4x6
A =24cm2
21-Jul-15
8cm
4cm
6cm
Area of a Composite
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Calculate the area of this shape
Rectangle 1
16cm
A=lxb
5cm
A = 16 x 5
A = 80cm2
5cm
6cm
21-Jul-15
Rectangle 2
A=lxb
A=6x5
A = 30cm2
Created by Mr. Lafferty Maths Dept.
Total Area
= 80 + 30
2
=110cm
Area of a Composite
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Now try Exercise 4
Ch10 (page 128)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Q1.
Calculate 5% of £220
Q2.
True or false the perimeter of the shape is 130cm
and the area is 46cm.
13cm
Q3.
Solve
Q4.
Convert 57 metres to
(a) cm
(b)
mm
21-Jul-15
6x  64  8
10cm
Created by Mr. Lafferty Maths Dept.
Area of
A Right-Angled Triangle
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Learning Intention
1. Develop the formula for
the area of any
right-angled triangle.
Success Criteria
1. Remember the area formula
for a right-angled triangle.
2. Use formula to work out
area of triangle.
3. Show all working and
units.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Area of
A Right-Angled Triangle
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Calculate the area of this shape
A=lxb
A = 10 x 8
8cm
21-Jul-15
A = 80cm2
10cm
Created by Mr. Lafferty Maths Dept.
Area of
A Right-Angled Triangle
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
1
Area= base × height
2
1
A= b×h
2
Vertical
Height
base
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Demo
Area of
A Right-Angled Triangle
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Calculate the area of this shape
1
A=  b  h
2
1
A=  6  12
2
12cm
6cm
21-Jul-15
A=36cm
2
Created by Mr. Lafferty Maths Dept.
Area of
A Right-Angled Triangle
MNU 2-11b
MNU2-11c
MTH 3-11b
www.mathsrevision.com
Calculate the area of this shape
3cm
4cm
1
A=  b  h
2
1
A=  4  3
2
A=6cm
2
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Area of
A Right-Angled Triangle
www.mathsrevision.com
MNU 2-11b
MNU2-11c
MTH 3-11b
Now try Exercise 6
Ch10 (page 129)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Scale Drawing
Scale 1cm to 0.5m
Length 4.5m = 9cm on the scale drawing
Length 6m = 12 cm on the scale drawing
For carpet grip we need to calculate PERIMETER
4m
Perimeter = 6 + 3 + 2 + 1.5 + 4 + 4.5 = 21m
(8cm)
4.5m (9cm)
(3cm) 1.5m
2m
(4cm)
Number of 1 metre grips = 21
No of packs = 21 ÷ 5 = 4.2 packs
So we need 5 packs
Cost = 5 x £ 4.50 = £22.50
(6cm) 3m
(12cm)
6m
Fitting carpet means we need to calculate AREA
Minimum Area required = 18 + 6 = 24m2
4m
4.5m
Area = L x B
= 4 x 4.5
= 18m2
6m
1.5m
2m
6m2
Remember the
carpet only comes
4m wide !
3m
What’s the best
way to fit it ?
Minimum AREA required = 18 + 6 = 24m2
One possible solution
4m
1.5m
2m
Area
4 x 6.5
= 26m2
4.5m
3m
2m
6m
Total cost £22.50 + £312 = £334.50
Cost
£12 x 26
= £ 312
With a bit left over !
Minimum AREA required = 18 + 6 = 24m2
Best possible solution
4m
1.5m
2m
Area
4x6
= 24m2
4.5m
3m
6m
Total cost £22.50 + £288 = £310.50
Cost
£12 x 24
= £ 288
Nothing left over !