Transcript Slide 1

Net and Surface Area
www.mathsrevision.com
Level 2
Faces Edges and Vertices
The Cube
The Cuboid
The Triangular Prism
21-Jul-15
Compiled by Mr. Lafferty Maths Dept.
Starter Questions
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Level 2
1.
Find the area a rectangle with length 6cm
and breadth 18cm.
2.
Calculate -14-(-8)
3.
Calculate the percentage
value of the shaded area.
4.
Change 692cm into metres.
21-Jul-15
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Faces Edges and Vertices
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Level 2
Learning Intention
1. We are learning the
meaning of Face, Edge and
Vertex.
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Success Criteria
1. Understand the terms
Face Edge and Vertex.
2. Calculate the number of
Faces Edges and Vertices
for various shapes.
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Don’t forget the
faces edges and
corners we can’t see
at the back
Face Edges and Vertices
Level 2
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The shape below is called a cuboid.
It is made up of FACES, EDGES and VERTICES.
Edges are where
the two faces
meet (lines)
Faces are the
sides of a shape
(surface area)
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Vertices where
lines meet
(corners)
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Calculate the number
of faces edges and
vertices for a cuboid.
Face Edges and Vertices
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Level 2
6 faces
Front and back are the same
Top and bottom are the same
Right and left are the same
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12 edges
8 vertices
Calculate the number
of faces edges and
vertices for a cube.
Face Edges and Vertices
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Level 2
6 faces
12 edges
Faces are squares
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8 vertices
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Name and then
calculate the number
of faces, edges and
vertices for these
shapes
Face Edges and Vertices
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Level 2
Cone
2 faces
1 edge
1 vertex
Cylinder
3 faces
2 edges
0 vertices
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Triangular
Prism
5 faces
9 edges
6 vertices
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Sphere
1 face
0 edges
0 vertices
Starter Questions
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Level 2
1.
Find the area a rectangle with length 6cm
and perimeter 18cm.
2.
Calculate -14-8+(-8)
3.
Calculate the percentage
value of the shaded area.
4.
Change 692cm 3 into ml.
5.
What is the coordinate F(4,-4) reflected in the x-axis?
21-Jul-15
Compiled by Mr. Lafferty Maths Dept.
Net and Surface Area
The Cube
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Level 2
Learning Intention
1. We are learning the
term net.
Success Criteria
1. Understand the term net.
2. Decide if a diagram makes
a net for a cube.
3. Calculate the surface area
of a cube using previous
knowledge of area.
21-Jul-15
Compiled by Mr. Lafferty Maths Dept.
Net and Surface Area
The Cube
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Level 2
The net of a solid shape is the shape you would get
if it was made of cardboard and you “opened it up
and laid it out flat”.
Right
left Bottom
Top
Back
Front
Side
Side
6 faces
All congruent
All squares
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This is a NET
for the cube
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Net and Surface Area
The Cube
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Level 2
Now try Exercise 1
Ch20 (page 234)
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Net and Surface Area
The Cube
Level 2
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Question : Find the surface area of the cube below.
What do we know?
• Made up of 6 faces
• All the same (congruent)
• All squares
5cm
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Area = length x length
=
=
l
5
x
x
=
25 cm2
l
5
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Total
6 x 25 =
2
150cm
Net and Surface Area
The Cube
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Level 2
Now try Exercise 2
Ch20 (page 235)
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Starter Questions
Level 2
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9cm
2 cm
1.
Calculate the area of the shape.
2.
Write 3.56m in centimetres?
3.
Find the volume of a cube with length 6cm.
4.
80% of 300 people have blues.
How many of the people DO NOT have blue eyes.
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6cm
7 cm
Net and Surface Area
The Cuboid
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Level 2
Learning Intention
1. We are learning to draw
the net of a cuboid and
calcualte its surface area.
Success Criteria
1. Be able to draw a net of a
cuboid.
2. Calculate the surface area
of a cuboid using previous
knowledge of the area of a
rectangle.
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Net and Surface Area
The Cuboid
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Level 2
4cm
LS
3cm
5cm
6 faces
Top and bottom congruent
Front and back congruent
Left and right congruent
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Bottom
3cm
Back
RS
Top
3cm
Front
4cm
4cm
5cm
This is a NET for the cuboid
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Example
Level 2
Find the surface
area of the cuboid
Working
Front Area = l x b
2
= 5 x 4 =20cm
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DEMO
4cm
3cm
Top Area = l x b
2
= 5 x 3 =15cm
Side Area = l x b
2
= 3 x 4 =12cm
Total Area
5cm
Front and back are the same
Top and bottom are the same = 20+20+15+15+12+12
2
Right and left are the same
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= 94cm
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Net and Surface Area
The Cuboid
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Level 2
Now try Exercise 3
Ch20 (page 236)
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Starter Questions
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Level 2
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1.
A cube of length 10cm is filled with water.
What is the volume of liquid in litres.
2.
What is area of the triangle.
3.
60% of 500 pupils like Maths.
How many pupils like Maths.
How many pupils don't like Maths.
4.
How long is it from 6.45am to 14.22 hrs
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6cm
8cm
Net and Surface Area
Triangular Prism
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Level 2
Learning Intention
1. We are learning to draw
the net of a triangular
prism.
Success Criteria
1. Be able to draw a net of a
triangular prism.
2. Calculate the surface area
of a right-angled triangular
prism using the area
formulae for a rectangle and
triangle.
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Net and Surface Area
Triangular Prism
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Level 2
Bottom
4cm
10cm
BT
4cm
Front
5 faces
3 congruent rectangles
2 congruent triangles
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Back
4cm
FT
4cm
10cm
This is a NET for the triangular prism.
Compiled by Mr. Lafferty Maths Dept.
Example
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Level 2
Find the surface area
of the right angle
prism
5cm
3cm
10cm
4cm
2 triangles the same
1 rectangle 3cm by 10cm
1 rectangle 4cm by 10cm
1 rectangle 5cm by 10cm
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Working
Triangle Area =
1
bh
2
2
= 2 x3 =6cm
Rectangle 1 Area = l x b
2
= 3 x10 =30cm
Rectangle 2 Area = l x b
2
= 4 x 10 =40cm
Rectangle 3 Area = l x b
2
= 5 x 10 =50cm
Total Area
2
= 6+6+30+40+50 = 132cm
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Net and Surface Area
Triangular Prism
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Level 2
Now try Exercise 4
Ch20 (page 239)
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Compiled by Mr. Lafferty Maths Dept.