Lecture 2 - Geometry 2D Shapes Flashcards
What is geometry?
Study of shape, space and measurement
1D lines
2D shapes
3D objects
How to teach geometry
Following the language model
Development of spatial intuition
Study of space
What are Hoffer’s 5 skills of geometry?
Visualising
Communication
Drawing and modelling
Thinking and reasoning (thinking logically)
Applying geometric concepts and knowledge
What is happening at skill 1?
Visualising
Students develop mental picture of the shape
Skill 2?
Communication
Students encouraged to talk and write about shapes and patterns as well as describe figures
Skill 3?
Drawing and modelling
Sketching and drawing 2D shapes
Modelling 3D objects
Drawing and modelling to scale
Skill 4?
Thinking logically
Classifying and analysing
Looking for differences and similarities
Skill 5?
Applying geometric concepts and knowledge
We teach geometry because of its value beyond the classroom
Real word jobs and mapping etc.
Common 2D shapes
Pentagon Heptagon Nonagon Dodecagon Hexagon Octagon Decagon
Commonly used attribute terms
Regular sides
Irregular or non regular
Similar
Congruent
Symmetry
Convex
What types of triangles are there
Right angle
Acute
Obtuse
Equilateral
Isosceles
Scalene
Features of a triangle
3 sides
3 angles
And sum of angles add up to 180 degrees
What is a quadrilateral
A plane figure with 4 sides 4 angles which sum to 360 degrees
Misconceptions of geometry
Show different orientations of shapes
Remember the 3D’s - decide, do and describe
Importance of timing when teaching formulas
Recall the language stages to build a strong foundational base for geometric understanding.
Students must explore and create formulas in their own words before using symbols.
