Transcript Perimeter Shapes Angles Revision

First we need to find the length of each side by
counting the squares.
8 cm
6 cm
6 cm
The distance
around the outside
of a shape is called
the perimeter.
8 cm
The perimeter of the shape is 8 + 6 + 8 + 6 = 28cm.
18cm
18cm
What is the
perimeter of
each of these
shapes?
22cm
18cm
26cm
Now find the
perimeter of these
shapes. They are
not drawn to scale.
5cm
3cm
3cm
4cm
3cm
7cm
3cm
7cm
3cm
3cm
Perimeter = 18cm
4cm
3cm
3cm
3cm
3cm
4cm
4cm
3cm
Perimeter = 22cm
Perimeter = 28cm
5cm
3
c
m
7
c
m
3cm
3cm
3cm
3
c
m
3
c
m
5cm
To order Fractions
Learning Objective
Use a protractor to draw and
measure acute and obtuse
angles to the nearest degree.
What are the properties of
a protractor??
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A protractor
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2
4
Here is a standard protractor like you
use in the classroom.
When we use a protractor, we
need to line it up correctly.
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2
4
You need to make sure the protractor is lined up correctly.
Is this ready to measure the angle?
Were you right......................it wasn’t
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2
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Look for the upside down ‘T’ in the middle of
the straight line on your protractor.
This needs to be exactly on the vertex of
your angle.
We need to remember.....
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It doesn’t
matter which
way round the
angle is, you
ALWAYS need
to line the upside
down ‘T’ to the vertex
of the angle.
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2
4
Now you are ready.
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2
4
Read from the 0°, and follow the inner set of
numbers.
Once you reach 30° you need to be
careful!!!
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2
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You then need to look at the 1° markings on
the outer set of numbers.
What does it measure?
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1
This angle measures 35°.
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4
What does it measure?
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1
This angle measures......
2
4
What does it measure?
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1
This angle measures......
2
4
Mr Obtuse Angle
This is Obtuse. He’s
the husband of the
family.
He’s bigger than
Right and Acute .
He’s always inside,
and he always
measures between
90° and 180°
(depending on how
much dinner he’s
eaten!)
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Mrs. Right Angle
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This is me. I’m
Mrs. Right Angle.
I always measure
90°, my favourite
shape is a square,
and whats more,
no matter what
my husband tells
you, I’m always
right!
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Baby Acute Angle
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This is baby
Acute angle.
Isn’t he cute?!
He loves a hug,
and always has
his arms out
for cuddles!
He’s the
smallest of the
family,
measuring less
than 90°.
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2
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Reflex Angle
This
our0001
pet0100
dog,1011
Reflex.
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1010is1101
He’s always outside.
He’s only a pup at the moment so he measures
180°, but he can grow up to 360 °! So he’s
definitely the biggest angle. You’ll never see him
without that ball in his mouth either, horrid
thing!
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So, now you’ve met us, let’s see how
well
you
know
us...
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Who am I?
I always measure less than 90°
I’m the smallest angle
I’m very cute!
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I’m....
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2
4
Who am I?
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I’m always outside
I’m the biggest angle
I can measure
between 180° and
360°
1
2
4
I’m...
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1
Reflex Angle
2
4
Who am I?
0011 0010 1010 1101 0001 0100 1011
I always measure
between 90° and 180 °
I’m always inside
I’m bigger than
Right and Acute
1
2
4
I’m...
0011 0010 1010 1101 0001 0100 1011
1
2
4
Who’s left?
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2
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YOUR TASK!
1.
2.
3.
4.
Draw an angle
Estimate it’s size in degrees
Measure
Write what type of angle it is
To order Fractions,
Decimals and Percentages.
Learning Objective
Measure and calculate angles
at a point.
HOW
MANY
RIGHT
ANGLES
HOWMANY
MANYDEGREES
DEGREESIN
IN
HOW
IN A CIRCLE?
CIRCLE? LINE?
AASTRAIGHT
90°
WHAT ARE THESE ANGLES?
120 °
A
CALCULATE THE
MISSING REFLEX ANGLE
313°
47°
CALCULATE THE
MISSING STRAIGHT
LINE ANGLE
69°
111°
CALCULATE THE
MISSING REFLEX ANGLE
234°
126°
CALCULATE THE
MISSING STRAIGHT
LINE ANGLE
103°
35°
42°
Learning Objective
Calculate angles in a
triangle.
PROPERTY OF
TRIANGLES
The sum of all the angles equals
180º degrees.
60º
60º
+ 60º
60º
180º
60º 60º
WHAT IS THE
MISSING ANGLE?
?
70º 70º
70º
70º
+ ?
180º
WHAT IS THE
MISSING ANGLE?
?
30º
90º
90º
30º
+ ?
180º
WHAT IS THE
MISSING ANGLE?
?
60º 60º
60º
60º
+ ?
180º
WHAT IS THE
MISSING ANGLE?
?
78º
30º
30º
78º
+ ?
180º
WHAT IS THE
MISSING ANGLE?
?
40º
40º
40º
40º
+ ?
180º
Equilateral Triangle
All 3 Sides are equal in Length
All 3 interior angles are the same
Isosceles Triangle
Two Sides of equal Length
Two interior angles are the same
Scalene Triangle
No Sides of equal Length
All interior angles are different
Right-Angled Triangles
Right-Angled Triangles can be either
Isosceles or scalene triangles
They have an Interior angle of
Scalene Right Angled Triangle
90 degrees
Isosceles Right Angled Triangle
Learning Objective
Calculate angles in a
triangle.
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
L.O angles quiz
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
L.O angles quiz
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
?
acute
obtuse
reflex
right
WHAT IS THE MISSING
ANGLE?
?
60º 60º
WHAT IS THE MISSING
ANGLE?
?
25º
95º
WHAT IS THE MISSING
ANGLE?
?
65º 65º
WHAT IS THE MISSING
ANGLE?
?
74º
40º
WHAT IS THE MISSING
ANGLE?
?
40º
40º