Page 101 - Knowledge Organiser Yr8 24-25

Knowledge Base: Mathematics TOPIC 20: Understanding 3D Shapes Year 8 | Spring Term 2
By the end of this topic you should be able to:
• Name and recognize properties of 2D shapes
• Name and recognize properties of 3D shapes
• Find the faces, edges and vertices of a 3D shape
• Recognise the net of a 3D shape
• Find symmetry in 3D shapes
• Recognise and draw plans and elevations
• Make isometric drawings
• Convert between plans and elevations and isometric drawings
Language
Meaning
Example
Solid
A shape formed in 3 dimensions
Cubes, spheres and cones are solids
Prism
A 3D shape with constant cross section
Here is a triangular prism
Cross Section
The 2D shape made when a 3D solid cut along its length
Cross sections of a cylinder include circles and rectangles
Face
A flat surface of a solid
See worked example
Edge
The line where 2 faces meet
Vertex (plural "vertices")
The point where 3 or more edges meet
Net
A 2D shape that can be folded to form a solid
Front Side Plan
The view of a solid from the front The side view of a solid
The view from above of a solid
Remember!
A polygon is 2 2D shape Example: Octagon (8 sides)
A polyhedron is a 3D shape Example: Octahedron (8 faces)
Worked examples
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