CN202331983U

CN202331983U - Circumference angle theorem demonstration instrument

Info

Publication number: CN202331983U
Application number: CN2011204684524U
Authority: CN
Inventors: 陈长虹
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-11-23
Filing date: 2011-11-23
Publication date: 2012-07-11
Anticipated expiration: 2021-11-23

Abstract

The utility model aims at providing a circumference angle theorem demonstration instrument. The circumference angle theorem demonstration instrument comprises a substrate, wherein a T-shaped slot is arranged on the substrate; the T-shaped slot extends for one circle around the circumference and corresponding circle center angles are marked; three T-shaped heads which can rotate and slide in the T-shaped slot are arranged in the T-shaped slot; the part of each T-shaped head is limited in the T-shaped slot; the other part of the T-shaped head stretches out; a pointer is fixed at the stretching part of the first T-shaped head; the pointer slides and passes through a through hole at the stretching part of the second T-shaped head; a pointer is fixed at the stretching part of the third T-shaped head; the pointer slides and passes through the other through hole at the stretching part of the second T-shaped head; and a protractor for measuring the included angle of two pointers is sleeved on the second T-shaped head.

Description

Angle of circumference theorem demonstrator

Technical field

The utility model relates to a kind of angle of circumference theorem demonstrator.

Background technology

As everyone knows, angle of circumference theorem: an arc right angle of circumference equal it right central angle half the.In mathematical education,, can not understand very soon because the student contacts first.Mathematics teaching aid (for example compasses, ruler etc.) can not be showed this theorem intuitively.

Summary of the invention

The technical matters that the utility model will solve provides a kind of angle of circumference theorem demonstrator.

In order to solve the problems of the technologies described above, the technical scheme of the utility model is:

A kind of angle of circumference theorem demonstrator comprises substrate, and substrate is provided with T-slot; T-slot circumferentially extends a week and the corresponding center of circle of a mark angle, is provided with 3 T shape heads that can in T-slot, rotate and slide in the T-slot, and the part of each T shape head is limited in the T-slot; Another part stretches out; The extension of first T shape head is fixed with a pointer, and the open-work of the extension of second T shape head is passed in the pointer slip, and the extension of the 3rd T shape head is fixed with a pointer; Another open-work of the extension of second T shape head is passed in the pointer slip, is with the protractor of measuring two pointer angles on second T shape head.

Said T shape head comprises major part and microcephaly, and the microcephaly connects with major part is rotatable.

The utility model constitutes two crossing strings through two pointers, and the angle of two pointers is an angle of circumference, can read central angle through the scale on the T-slot, an arc right angle of circumference equal it right central angle half the just obtain checking very intuitively.

Description of drawings

Below in conjunction with accompanying drawing the embodiment of the utility model is done further detailed explanation:

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

Fig. 2 is the structural drawing of T shape head.

Among the figure: 1 substrate, 2T shape groove, 3 protractors, 4 pointers, 5T shape head, 51 microcephalies, 52 major parts.

Embodiment

As shown in Figure 1, a kind of angle of circumference theorem demonstrator comprises substrate 1; Substrate is provided with T-slot 2, and T-slot circumferentially extends a week and the corresponding center of circle of a mark angle, is provided with 3 the T shapes that can in T-slot, rotate and slide 5 in the T-slot; The part of each T shape head is limited in the T-slot, and another part stretches out, and the extension of first T shape head is fixed with a pointer 4; The open-work of the extension of second T shape head is passed in the pointer slip; The extension of the 3rd T shape head is fixed with a pointer, and another open-work of the extension of second T shape head is passed in the pointer slip, is with the protractor 3 of measuring two pointer angles on second T shape head.

As shown in Figure 2, said T shape head comprises major part 52 and microcephaly 51, and the microcephaly connects with major part is rotatable.

Claims

1. angle of circumference theorem demonstrator, it is characterized in that: comprise substrate, substrate is provided with T-slot; T-slot circumferentially extends a week and the corresponding center of circle of a mark angle, is provided with 3 T shape heads that can in T-slot, rotate and slide in the T-slot, and the part of each T shape head is limited in the T-slot; Another part stretches out; The extension of first T shape head is fixed with a pointer, and the open-work of the extension of second T shape head is passed in the pointer slip, and the extension of the 3rd T shape head is fixed with a pointer; Another open-work of the extension of second T shape head is passed in the pointer slip, is with the protractor of measuring two pointer angles on second T shape head.

2. angle of circumference theorem demonstrator according to claim 1 is characterized in that: said T shape head comprises major part and microcephaly, and the microcephaly connects with major part is rotatable.