Geometry Flashcards
What are the geometry sub strands? 3
Shape - 2D and 3D
Location and transformation
Geometric reasoning
What are the 5 steps in the van heile model of developing geometric thinking?
1) visualising - judge figures by appearance
2) analysis -
3) informal diductions
4) formal deductions
5) rigour
What is VH theory 1?
Visualisation - students recognise basic shapes by appearance
What is VH level 2?
- students recognise shapes by their properties
- rotated square is still a square because of same properties
What is VH level 3?
- students recognise relationships between families of shapes
Plane figures that are not polygons include
Circles and ovals
Complex figures
Open curves
Shapes with rounded corners
Polygons are regular if
All sides lengths and angles are equal
What are examples of regular polygons
Equilateral triangle
Square
Regular pentagon
Regular hexagon
Polygons are irregular if?
Not all side lengths or angles are equal
What are some examples of irregular polygons?
Isosceles triangle, rectangle, irregular pentagon, irregular hexagon
Triangles are classified by either ?
Their side or angle properties or both
An equilateral triangle has
3 equal sides
An isosceles triangle has?
2 equal sides
A scalene triangle has
No equal sides
An acute angle has
All angles acute
A right sided triangle has a
90 degree angle
An obtuse triangle has
An angle less than 90 degrees
What is a net?
A 2D pattern that can be cut and folded to make a pattern of a 3D shape
What is a polyhedron?
3D solid shape where it’s faces are polygons
With a polyhedron, edges are formed when?
2 faces meet
Polyhedrons include which shapes?
Prisms, pyramids and Platonic solids
3D shapes that are not polyhedrons include
Spheres, cylinders, cones
What is a prism?
A 3D object created by 2 polygon faces joined by rectangles
Prisms are named after
The shape of the polygon on which it is based
