Difference between revisions of "Constructive Triangles: Third Box"
From wikisori
Line 1: | Line 1: | ||
=== Age === | === Age === | ||
− | 6-9.<br> | + | 6-9.<br> |
=== Materials === | === Materials === | ||
Line 11: | Line 11: | ||
=== Preparation === | === Preparation === | ||
− | <br> | + | <br> |
=== Presentation === | === Presentation === | ||
− | #Isolate one triangle. | + | #Isolate one triangle. |
− | #Ask the child to identify each of the angles, and the biggest and smallest angles. | + | #Ask the child to identify each of the angles, and the biggest and smallest angles. |
− | #This angle which is neither smallest nor biggest we can call the medium angle. | + | #This angle which is neither smallest nor biggest we can call the medium angle. |
− | #The child names each angle: smallest angle, medium angle, biggest angle. | + | #The child names each angle: smallest angle, medium angle, biggest angle. |
#First star: Let's unite all the triangles by their smallest angle. | #First star: Let's unite all the triangles by their smallest angle. | ||
#The directress positions a few and allows the child to continue. | #The directress positions a few and allows the child to continue. | ||
#How many points does this star have? Twelve. | #How many points does this star have? Twelve. | ||
− | #With all of the triangles at our disposal, we can make only one star with twelve points. | + | #With all of the triangles at our disposal, we can make only one star with twelve points. |
#Second star: Let's unite all the triangles by the medium angles. | #Second star: Let's unite all the triangles by the medium angles. | ||
#How many points does this star have? Six. | #How many points does this star have? Six. | ||
#Try to make another star with the triangles that are left. | #Try to make another star with the triangles that are left. | ||
− | #With all the triangles at our disposal, we can make two stars with six points. | + | #With all the triangles at our disposal, we can make two stars with six points. |
− | #Third star: Let's unite all of the triangles by the largest angle. | + | #Third star: Let's unite all of the triangles by the largest angle. |
#How many points does this star have? Four. | #How many points does this star have? Four. | ||
− | #This symbol is very famous; it is the star of Saint Brigid, the patron saint of Ireland. | + | #This symbol is very famous; it is the star of Saint Brigid, the patron saint of Ireland. |
#Try to make another star like this. | #Try to make another star like this. | ||
#With all the triangles at our disposal, we can make three stars with four points.<br> | #With all the triangles at our disposal, we can make three stars with four points.<br> | ||
Line 35: | Line 35: | ||
=== Control Of Error === | === Control Of Error === | ||
− | <br> | + | <br> |
=== Points Of Interest === | === Points Of Interest === | ||
− | <br> | + | <br> |
=== Purpose === | === Purpose === | ||
− | + | Use of the triangle as a constructor to indirectly demonstrate the following: | |
+ | |||
+ | *30<sup>o</sup> x 12 triangles = 360<sup>o</sup> | ||
+ | *60<sup>o</sup> x 6 triangles = 360<sup>o</sup> | ||
+ | *90<sup>o</sup> x 4 triangles = 360<sup>o</sup> | ||
+ | *360<sup>o</sup> / 30<sup>o</sup> = 12 triangles | ||
+ | *360<sup>o</sup> / 60<sup>o</sup> = 6 triangles | ||
+ | *360<sup>o</sup> / 90<sup>o</sup> = 4 triangles | ||
+ | *360<sup>o</sup> / 12 triangles = 30<sup>o</sup> | ||
+ | *360<sup>o</sup> / 6 triangles = 60<sup>o</sup> | ||
+ | *360<sup>o</sup> / 4 triangles = 90<sup>o</sup><br> | ||
=== Variation === | === Variation === | ||
− | <br> | + | <br> |
=== Links === | === Links === | ||
+ | [http://jmjpublishing.com/JMJpdfs4all/09ConstTriangles1-5.pdf Constructive Triangles Boxes # 1-5] <br> | ||
− | <br> | + | <br> |
=== Handouts/Attachments === | === Handouts/Attachments === | ||
− | <br> | + | <br> |
[[Category:Mathematics]] [[Category:Mathematics_6-9]] | [[Category:Mathematics]] [[Category:Mathematics_6-9]] |
Revision as of 03:14, 4 January 2010
Contents
Age
6-9.
Materials
Box 3 -
- Twelve blue right-angled scalene triangles with no black lines. The angles measure 30, 60, and 90 degrees.
Preparation
Presentation
- Isolate one triangle.
- Ask the child to identify each of the angles, and the biggest and smallest angles.
- This angle which is neither smallest nor biggest we can call the medium angle.
- The child names each angle: smallest angle, medium angle, biggest angle.
- First star: Let's unite all the triangles by their smallest angle.
- The directress positions a few and allows the child to continue.
- How many points does this star have? Twelve.
- With all of the triangles at our disposal, we can make only one star with twelve points.
- Second star: Let's unite all the triangles by the medium angles.
- How many points does this star have? Six.
- Try to make another star with the triangles that are left.
- With all the triangles at our disposal, we can make two stars with six points.
- Third star: Let's unite all of the triangles by the largest angle.
- How many points does this star have? Four.
- This symbol is very famous; it is the star of Saint Brigid, the patron saint of Ireland.
- Try to make another star like this.
- With all the triangles at our disposal, we can make three stars with four points.
Control Of Error
Points Of Interest
Purpose
Use of the triangle as a constructor to indirectly demonstrate the following:
- 30o x 12 triangles = 360o
- 60o x 6 triangles = 360o
- 90o x 4 triangles = 360o
- 360o / 30o = 12 triangles
- 360o / 60o = 6 triangles
- 360o / 90o = 4 triangles
- 360o / 12 triangles = 30o
- 360o / 6 triangles = 60o
- 360o / 4 triangles = 90o
Variation
Links
Constructive Triangles Boxes # 1-5
Handouts/Attachments