Constructive Triangles: First Box

Age
6-9.

Materials
Box 1-


 * Two yellow equilateral triangles
 * Two yellow, two green right-angled isosceles triangles
 * Two yellow, two green, two gray right-angled scalene triangles
 * One red smaller right-angled scalene triangle
 * On red obtuse-angled scalene triangle (Each triangle has a black line along one side)

Presentation

 * 1) Invite the child to remove the triangles from the box, and then sort the triangles according to shape.
 * 2) Having done this, ask the child to separate each pile according to color, resulting in various piles of triangles having both shape and color in common.
 * 3) Isolate the two red ones to be used later.
 * 4) The directress takes the pile of two equilaterals and separates them in such a way that the two black lines are facing each other.
 * 5) Watch, these black lines are like a magnet.
 * 6) Slide the two triangles together so that the black lines meet.
 * 7) Invite the child to do the same, leaving the joined triangles in place.
 * 8) Identify the figures that have been constructed: a yellow rhombus, a green square, and a gray rectangle.
 * 9) The directress identifies the other three figures as common parallelograms (parallelogram: Greek parallelogramium &lt;parallelos, parallel, and grame, figure&gt;).
 * 10) Therefore a parallelogram is a plane figure having parallel sides.
 * 11) By simultaneously running two fingers along two parallel sides, the directress gives a sensorial impression of parallel.
 * 12) We also call them common parallelograms to differentiate them from the square, rectangle, and rhombus which could also be considered parallelograms.
 * 13) The child names each figure as they are indicated by the directress.

Handouts/Attachments
Constructive Triangles Boxes # 1-5