Difference between revisions of "Visualising solid shapes"
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=== Prerequisites/Instructions, prior preparations, if any === | === Prerequisites/Instructions, prior preparations, if any === | ||
+ | Prior knowledge about 2D shapes and its properties | ||
=== Materials/ Resources needed === | === Materials/ Resources needed === | ||
+ | Digital: Laptop, geogebra file, projector and a pointer. | ||
=== Process (How to do the activity) === | === Process (How to do the activity) === | ||
{{Geogebra|g7crjrpd}} | {{Geogebra|g7crjrpd}} | ||
− | + | * "What are some shapes that you know?" | |
− | + | * Show picture of 2d and 3d and ask difference among shapes, What's the difference between 2D and 3D shapes? | |
− | + | * Invite students to share the names of 2D and 3D shapes | |
− | + | * What are 3 D shapes? | |
− | + | * Visualizing solid shapes is a very useful skill. You should be able to see ‘hidden’parts of the solid shape. | |
− | + | * Different sections of a solid can be viewed in many ways: | |
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(a) One way is to view by cutting or slicing the shape, which would result in the | (a) One way is to view by cutting or slicing the shape, which would result in the | ||
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(b) Another way is by observing a 2-D shadow of a 3-D shape. | (b) Another way is by observing a 2-D shadow of a 3-D shape. | ||
− | (c) A third way is to look at the shape from different angles; the front-view, the | + | (c) A third way is to look at the shape from different angles; |
− | + | * the front-view, the side-view and the top-view can provide a lot of information about the shape observed. | |
− | + | * Rotate the object to find a top, side and bottom view of the solid. | |
− | + | * Draw these views using pencil in your maths books, with a title "Top, side and bottom views of objects." | |
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− | |||
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− | + | {{Geogebra|uk9caecz}} | |
+ | * Do you remember the Faces, Vertices and Edges of solid shapes | ||
+ | * Students recall the terms edge, vertex, and face. | ||
Face- part of a 3D shape that is flat | Face- part of a 3D shape that is flat | ||
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Base – the bottom base of a 3D shape | Base – the bottom base of a 3D shape | ||
− | + | * Can you see that, the two-dimensional figures can be identified as the faces of the three-dimensional shapes? | |
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'''Cuboid''' | '''Cuboid''' | ||
{{Geogebra|xwfryemq}} | {{Geogebra|xwfryemq}} | ||
− | + | # How many sides does a cuboid have ? | |
− | + | # Are all sides the same ? | |
+ | # Point to its vertices. How many vertices does a cuboid have ? | ||
+ | # Point to its edges and faces. How many are there ? | ||
+ | # What is the shape of each of its face ? So how many squares and rectangles are there in a cuboid ? | ||
+ | # Observe that shapes have two or more than two identical(congruent)faces?name them? | ||
+ | # What are the properties of a cuboid ? | ||
'''Cube''' | '''Cube''' | ||
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{{Geogebra|efqkt9am}} | {{Geogebra|efqkt9am}} | ||
− | + | # How many sides does a cube have ? | |
+ | # Are all sides the same ? | ||
+ | # Point to its vertices. How many vertices does a cube have ? | ||
+ | # Point to its edges and faces. How many are there ? | ||
+ | # What is the shape of each of its face ? So how many squares are there in a cube ? | ||
+ | # Which solids has all congruent faces? | ||
+ | # What are the properties of a cube ? | ||
'''Cylinder''' | '''Cylinder''' | ||
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{{Geogebra|p6fv452u}} | {{Geogebra|p6fv452u}} | ||
− | + | # How many bases are in a cylinder? | |
+ | # What shape is the base of a cylinder? | ||
+ | # How many edges does a cylinder have ? | ||
+ | # How many vertices does a cylinder have ? | ||
+ | # How many faces does a cylinder have ? | ||
+ | # What are the properties of a cylinder? | ||
'''Cone''' | '''Cone''' | ||
{{Geogebra|a74exedh}} | {{Geogebra|a74exedh}} | ||
+ | |||
+ | # What shape is the base of a cone? | ||
+ | # How many edges does a cone have ? | ||
+ | # How many vertices does a cone have ? | ||
+ | # How many faces does a cone have ? | ||
+ | # What are the properties of a cone? | ||
'''Sphere''' | '''Sphere''' | ||
{{Geogebra|m7hwxbp7}} | {{Geogebra|m7hwxbp7}} | ||
+ | # How many edges does a sphere have ? | ||
+ | # How many vertices does a sphere have ? | ||
+ | # How many faces does a sphere have ? | ||
+ | # What are the properties of a sphere? | ||
− | + | * Does the base of the shape change depending on how the shape is positioned? | |
− | + | * Observe the shape of each face and find the number of faces of the box that are identical by placing them on each other. Write down your observations. | |
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Cuboidal box – all six faces are rectangular, and opposites faces are identical. So there are three pairs of identical faces. | Cuboidal box – all six faces are rectangular, and opposites faces are identical. So there are three pairs of identical faces. | ||
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Cylindrical Box – One curved surface and two circular faces which are identical. | Cylindrical Box – One curved surface and two circular faces which are identical. | ||
+ | * A net is a sort of skeleton-outline in 2-D, which, when folded results in a 3-D shape. ''' ''' | ||
+ | |||
+ | '''Euler’s formula for Polyhedrons (F+V=E+2)''' | ||
+ | |||
+ | {{Geogebra|bhseqkhj}} | ||
+ | * What are polyhedrons? | ||
+ | Polyhedrons - Is a 3D solid which with flat polygonal faces, straight edges and sharp corners or vertices. | ||
+ | * Identify number of edges, faces and vertices in a given polyhedron ? | ||
− | + | * Calculate F+V and E+2 | |
− | + | * F+V = E+2 (Euler's Formula or Polyhedral formula) | |
− | + | * F+V-E=2 | |
+ | |||
+ | * The number of faces plus the number of vertices minus the number of edges equals 2. |
Revision as of 13:28, 5 June 2021
Objectives
1. Understanding the difference between 2D figures and 3D figures
2. Identify views of 3D objects
3. Make a connection between everyday objects and 3D shapes
4. Students will be able to describe 3D shapes
5. Verifying Euler’s formula for Polyhedrons.
Estimated Time
90 minutes
Prerequisites/Instructions, prior preparations, if any
Prior knowledge about 2D shapes and its properties
Materials/ Resources needed
Digital: Laptop, geogebra file, projector and a pointer.
Process (How to do the activity)
Download this geogebra file from this link.
- "What are some shapes that you know?"
- Show picture of 2d and 3d and ask difference among shapes, What's the difference between 2D and 3D shapes?
- Invite students to share the names of 2D and 3D shapes
- What are 3 D shapes?
- Visualizing solid shapes is a very useful skill. You should be able to see ‘hidden’parts of the solid shape.
- Different sections of a solid can be viewed in many ways:
(a) One way is to view by cutting or slicing the shape, which would result in the
cross-section of the solid.
(b) Another way is by observing a 2-D shadow of a 3-D shape.
(c) A third way is to look at the shape from different angles;
- the front-view, the side-view and the top-view can provide a lot of information about the shape observed.
- Rotate the object to find a top, side and bottom view of the solid.
- Draw these views using pencil in your maths books, with a title "Top, side and bottom views of objects."
Download this geogebra file from this link.
- Do you remember the Faces, Vertices and Edges of solid shapes
- Students recall the terms edge, vertex, and face.
Face- part of a 3D shape that is flat
Edge-two faces meet at a line segment( A line where two faces meet in 3D shape)
Vertex- three or more edges meet at a pointuk9caecz
Base – the bottom base of a 3D shape
- Can you see that, the two-dimensional figures can be identified as the faces of the three-dimensional shapes?
Cuboid
Download this geogebra file from this link.
- How many sides does a cuboid have ?
- Are all sides the same ?
- Point to its vertices. How many vertices does a cuboid have ?
- Point to its edges and faces. How many are there ?
- What is the shape of each of its face ? So how many squares and rectangles are there in a cuboid ?
- Observe that shapes have two or more than two identical(congruent)faces?name them?
- What are the properties of a cuboid ?
Cube
Download this geogebra file from this link.
# How many sides does a cube have ?
- Are all sides the same ?
- Point to its vertices. How many vertices does a cube have ?
- Point to its edges and faces. How many are there ?
- What is the shape of each of its face ? So how many squares are there in a cube ?
- Which solids has all congruent faces?
- What are the properties of a cube ?
Cylinder
Download this geogebra file from this link.
- How many bases are in a cylinder?
- What shape is the base of a cylinder?
- How many edges does a cylinder have ?
- How many vertices does a cylinder have ?
- How many faces does a cylinder have ?
- What are the properties of a cylinder?
Cone
Download this geogebra file from this link.
- What shape is the base of a cone?
- How many edges does a cone have ?
- How many vertices does a cone have ?
- How many faces does a cone have ?
- What are the properties of a cone?
Sphere
Download this geogebra file from this link.
- How many edges does a sphere have ?
- How many vertices does a sphere have ?
- How many faces does a sphere have ?
- What are the properties of a sphere?
- Does the base of the shape change depending on how the shape is positioned?
- Observe the shape of each face and find the number of faces of the box that are identical by placing them on each other. Write down your observations.
Cuboidal box – all six faces are rectangular, and opposites faces are identical. So there are three pairs of identical faces.
Cubical box – All six faces are squares and identical
Cylindrical Box – One curved surface and two circular faces which are identical.
- A net is a sort of skeleton-outline in 2-D, which, when folded results in a 3-D shape.
Euler’s formula for Polyhedrons (F+V=E+2)
Download this geogebra file from this link.
- What are polyhedrons?
Polyhedrons - Is a 3D solid which with flat polygonal faces, straight edges and sharp corners or vertices.
- Identify number of edges, faces and vertices in a given polyhedron ?
- Calculate F+V and E+2
- F+V = E+2 (Euler's Formula or Polyhedral formula)
- F+V-E=2
- The number of faces plus the number of vertices minus the number of edges equals 2.