Presentation of the Materials: Triangles
Contents |
Age
6-9.
Materials
- Insets of the fractional parts of a triangle
- Geometry charts... triangle 1,2,3,4
Preparation
Presentation
- Bring out the four insets.
- Identify the whole triangle: equilateral, whole, unit.
- Identify the others in the same way as before: the number of equal parts, how they were formed, the value of each resulting piece.
- The same triangle was divided into two equal parts by the height.
- Each has the value of 1/2.
- The same triangle was divided into three equal parts by the angle bisectors extending to the point of intersection.
- Each has the value of 1/3.
- The same triangle was divided into four equal parts by finding the midpoints of the sides and joining them.
- Each has the value of 1/4.
- Classify the triangles which have been formed: 1/2 - right-angled scalene triangle; 1/3 - obtuse-angled isosceles triangle; 1/4 - equilateral triangle. show chart 1.
- Examine the relationship between the lines of the fractional triangles and the whole.
- Show charts 2,3 and 4.
Control Of Error
Points Of Interest
Purpose
Variation
The child may construct his own charts.
Links
Handouts/Attachments
