CN2164083Y

CN2164083Y - Multifunction triangle and quadrilateral demonstrating model

Info

Publication number: CN2164083Y
Application number: CN 93205999
Authority: CN
Inventors: 马凯
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-09
Filing date: 1993-03-09
Publication date: 1994-05-04
Anticipated expiration: 2003-03-09

Abstract

The utility model provides an innovative and improved triangle and quadrilateral demonstrating model for the teaching in primary schools. The utility model is characterized in that a square ABCD whose side length is equal to 12 cm is welded by a metal wire; an isosceles side B'C' of an isosceles right triangle ABC is connected with a side BC of the square; two congruent isosceles right triangles A'D'H and CDH are connected with two hinges; a base A'D' of the isosceles right triangle A'D'H is connected with a side AD of the square. The utility model can form a square, a rectangle, various triangles, a parallelogram and a trapezoid. 55 problems in the teaching for primary mathematics can be demonstrated.

Description

Multifunction triangle and quadrilateral demonstrating model

The utility model provides a kind of multi-functional triangle and quadrilateral demonstrating model, is a kind of innovation and significantly improved geometric knowledge teaching demonstration model is arranged.

In existing technology, generally be to utilize strawboard or waste paper sheet to be cut into coarse triangle and quadrilateral, like this can not active presentation, do not reach one-object-many-purposes again, be exactly condition preferably its teaching aid of school be: therefore triangle model can only be demonstrated triangulation problem, and the quadrilateral model can only be demonstrated the quadrilateral problem and cause that the teaching aid number of packages is many, manufacturing cost high price expense.

Seeking the purpose of this utility model is to be to improve the primary school math teaching quality, and the triangle and the quadrilateral demonstrating model of a kind of simple in structure, demonstration convenience, visual pattern, one-object-many-purposes, low cost of manufacture is provided.

Major technique feature of the present utility model is: the length of side that it is provided with welded wire is the square ABCD of 12cn, and isosceles right triangle B ' EC ' and EFC ' equaling square one medium-sized two congruences connect together with two hinges.At equilateral triangle B ' NN of the middle welding of isosceles right triangle B ' EC ', waist B ' C ' of waist B ' C ' of isosceles right triangle B ' EC ' is connected on the BC limit of square ABCD with two hinges.Isosceles right triangle A ' D ' the H and the D ' CH that equal square 1/4th big two congruences are connected together with two hinges, and have isosceles right triangle A ' D ' H end A ' D ' to be connected on the foursquare limit AD.The utility model just can be demonstrated square, rectangle, various triangle, parallelogram and trapezoidal relevant issues like this.

Hinge is that the foil with certain-length is rolled into the cylinder that is a bit larger tham wire diameter respectively inwards from its positive and negative, two ends, in tinsel is wrapped in, matches with its people, can be movable folding.

The utility model has the advantages that:

1, because the model structure of employing welded wire is simple, easily manufactured, price is low, physical life is long.

2, one-object-many-purposes, in the preliminary teaching of plane geometry knowledge, it can demonstrate leg-of-mutton relevant issues, can demonstrate tetragonal relevant issues again, and it can demonstrate 55 problems in the preliminary teaching of geometric knowledge.

3, since adopt welded wire, with hinge link, can be movable folding, demonstration is convenient, visual and understandable.

Description of drawings:

Fig. 1 is a structural drawing of the present utility model

Fig. 2 is demonstration square and rectangular folding figure

Fig. 3 is the folding figure of demonstration triangle and parallelogram

Fig. 4 is the folding figure of demonstration isosceles trapezoid

Fig. 5 is the folding figure of demonstration right-angled trapezium.

The utility model demonstration example, details are as follows in conjunction with the accompanying drawings:

It can demonstrate leg-of-mutton definition, classification, has by the angle branch: oxygon, right-angle triangle and obtuse triangle; There are scalene triangle, isosceles triangle and equilateral triangle, the leg-of-mutton end, height, area to demonstrate ten problems altogether by the limit branch.For example, when demonstrating leg-of-mutton definition, see Fig. 3, B ' EC ' and B ' NN are the figures that is surrounded by three line segments, are called triangle.And for example, demonstrate leg-of-mutton classification and see accompanying drawing 2, by the limit branch scalene triangle is arranged, as triangle B ' C ' N, isosceles triangle is as triangle A ' D ' G, equilateral triangle B ' NN.

It can also demonstrate the definition of isosceles triangle, and two base angles equate that the end, height, drift angle, area axis of symmetry, symmetric figure be totally eight problems.For example, during the definition of demonstration isosceles triangle, see accompanying drawing 3, waist D ' G, D ' G and the A ' D ' of folding isosceles right triangle D ' GH overlap fully, and two waist A ' D ' and D ' G equate, so triangle A ' D ' G is an isosceles triangle.Use the same method and to demonstrate isosceles triangle two base angles and equate.

It can also demonstrate the definition, the end of equilateral triangle, high each angle all is 60 °, area axis of symmetry and symmetric figure totally seven problems.For example, when each angle of demonstration equilateral triangle is 60 °, see accompanying drawing 3, triangle B ' NN three limits equate that per two angles equate that all promptly three angles equate, because Atria interior angle sum equals 180 °, so each angle of equilateral triangle is 60 °.

It can also demonstrate definition, the end, height and four problems of area of parallelogram.For example, during the definition of demonstration parallelogram, see accompanying drawing 3, one group of opposite side AE of quadrilateral parallel with GC (being that foursquare opposite side is parallel and equal), AE and GC equate, so quadrilateral AECG is called parallelogram.And for example, during the area of demonstration parallelogram, see accompanying drawing 3, high area in it is multiply by at the end of parallelogram, is folded into accompanying drawing 2 by accompanying drawing 3, and the area that can see parallelogram intuitively equals the end and multiply by height.

It can also demonstrate trapezoidal definition, classify, be isosceles trapezoid, right-angled trapezium and generally trapezoidal, upper base, go to the bottom, height and area totally ten five problems.For example, when demonstrating trapezoidal definition, it is trapezoidal to see that 4, one groups of parallel quadrilaterals of opposite side of accompanying drawing are called, and quadrilateral G ' E parallel with DC (opposite side of square ABCD) is so that quadrilateral G ' ECD is called is trapezoidal.And for example, during the definition of demonstration isosceles trapezoid, see accompanying drawing 4, to right folding, EC ' equals the diagonal line of square ABCD to left folding A ' C, and promptly two waists equate, so trapezoidal G ' ECD is an isosceles trapezoid.

It can also be demonstrated foursquare four edges and equate that opposite side is parallel, and four angles all are the right angles, and girth and area be totally five problems.For example: demonstrate square opposite side when parallel, see accompanying drawing 1, because AB and CD are cut by AD, the internal angles on the same side complementation, so AB ‖ CD, and for example: when demonstrating rectangular girth, see accompanying drawing 2, AEFD is a rectangle, and its girth is 2(AE+AD).Also can demonstrate rectangular opposite side and equate, opposite side equality, four angles all are the right angles, girth and area can be demonstrated 55 problems in the preliminary teaching of primary school mathematics geometric knowledge altogether.

Claims

1, a kind of primary school mathematics triangle and quadrilateral demonstrating model, it is characterized in that, it is provided with length of side of welded wire is the square ABCD of 12cm, with the isosceles right triangle B ' EC and the ADC that equal square one medium-sized two congruences, connect together with two hinges, constitute square A ' B ' C ' D ' that a length of side is 12cm, waist B ' C ' of isosceles right triangle B ' EC ' wherein is connected on the foursquare limit BC, isosceles right triangle A ' D ' the H and the GC ' H that equal square 1/4th big two congruences are connected together with two hinges, and end A ' D ' of isosceles right triangle A ' D ' H is connected on the foursquare limit AD, in order to forming parallelogram and trapezoidal.

2, triangle and the quadrilateral demonstrating model in preliminary according to the said primary school mathematics geometric knowledge of claim 1, it is characterized in that connecting with hinge, can be movable folding, it can demonstrate square, rectangle, various triangle, parallelogram and trapezoidal relevant issues.

3, according to said triangle of claim 1 and quadrilateral demonstrating model, it is characterized in that hinge is that foil with certain-length is rolled into the cylinder that is a bit larger tham wire diameter respectively inwards from its positive and negative, two ends, and match with it, can movable folding demonstration.