CN204382972U - A kind of instrument of Optional-angle trisecting - Google Patents
A kind of instrument of Optional-angle trisecting Download PDFInfo
- Publication number
- CN204382972U CN204382972U CN201420723155.3U CN201420723155U CN204382972U CN 204382972 U CN204382972 U CN 204382972U CN 201420723155 U CN201420723155 U CN 201420723155U CN 204382972 U CN204382972 U CN 204382972U
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- China
- Prior art keywords
- semi
- circular arc
- angle
- trisection
- straightway
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- 230000011514 reflex Effects 0.000 description 3
- 238000010276 construction Methods 0.000 description 2
- 241000276438 Gadus morhua Species 0.000 description 1
- 235000019516 cod Nutrition 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
Abstract
The utility model relates to a kind of instrument of Optional-angle trisecting, the straightway of the circular hole by the hollow out semi-circular arc on transparent plane meter plate, chi plate, circular arc circle centre position and two end points through semi-circular arc forms, 60 ° of described semi-circular arc and 120 ° of two places indicate scale, described straightway comprises section on the left of semi arch diameter segment diameter, and on the left of described diameter, the length of section is not less than semi arch radius.Coordinate any one jiao of compasses trisection with semi-circular arc and straightway, semi-circular arc is provided with 60 ° and 120 degree of scales, can the trisection straight angle, and avoid use set square, simple to operate, the trisection of an angle is accurate.
Description
Technical field
This utility model designs a kind of drafting instrument, Specifically relates to a kind of instrument of Optional-angle trisecting.
Background technology
The trisection of an angle is one of large geometrical issues of ancient Greek three.The trisection of an angle is the name topic in the middle of ancient Greek's geometric ruler mapping, and one of quadrature of a circle, the duplication of a cube Three Difficult Issues being listed as ancient mathematics, and the now has mathematically confirmed that this problem is without solution.The complete description of this problem is: only do not having graduated ruler by a given angle trisection with compasses and one.At construction with ruler and compasses namely with under the prerequisite not having graduated ruler and compasses construction, this topic is without separating.If condition is relaxed, such as, allow to use graduated ruler, or other curves can be coordinated to use, a given angle can be divided into trisection.
The trisection of an angle is deep-rooted in the heart at most people without the conclusion of separating, and have the method introduced and divide random angle equally in middle school teaching material, the problem for three isogonisms seldom relates to, and often adopts protractor to measure roughly when the needs trisection of an angle.
Summary of the invention
The purpose of this utility model there are provided one can the instrument of quick and precisely Optional-angle trisecting.
The technical scheme that the utility model is taked is
An instrument for Optional-angle trisecting, the straightway of the circular hole by the hollow out semi-circular arc on transparent plane meter plate, chi plate, circular arc circle centre position and two end points through semi-circular arc forms.
Further, 60 ° of described semi-circular arc and 120 ° of two places indicate scale.
Again further, described straightway comprises section on the left of semi arch diameter segment diameter, and on the left of described diameter, the length of section is not less than semi arch radius.
The utility model takes the beneficial effect of above technical scheme to be:
An instrument for Optional-angle trisecting, coordinate any one jiao of compasses trisection with semi-circular arc and straightway, semi-circular arc is provided with 60 ° and 120 degree of scales, can the trisection straight angle, and avoid use set square, simple to operate, the trisection of an angle is accurate.
Accompanying drawing explanation
Fig. 1 is structural scheme of mechanism of the present utility model;
Fig. 2-7 is the step schematic diagram of Optional-angle trisecting.
In figure: chi plate 1, straightway 2, semi arch starting point 3, semi arch 4, circle center hole 5, semi arch terminal 6,60 ° of scales 7,120 ° of scales 8.
Detailed description of the invention
Below in conjunction with embodiment, the utility model is further described:
As Fig. 1, a kind of instrument of Optional-angle trisecting comprises chi plate 1, straightway 2, semi arch starting point 3, semi arch 4, circle center hole 5, semi arch terminal 6,60 ° of scales 7 and 120 ° of scales 8, semi arch 6 is hollow out circular arc, circle center hole 5 is positioned at the circle centre position of semi arch 6, described circle center hole 5, semi arch starting point 3 and semi arch terminal 6, all on straightway 2, semi arch 4 are provided with 60 ° of scales 7 and 120 ° of scales 8.
A during any one bad angle ∠ AOB of the instrument trisection of Optional-angle trisecting, reverse extending ∠ AOB two limits, form vertical angles ∠ COD, as Fig. 2;
Utilize compasses to make the angular bisector also difference reverse extending of ∠ AOC and ∠ AOB, form transverse axis x-axis and longitudinal axis y-axis, as Fig. 3;
Overlapped with O point by circle center hole on chi plate 1, straightway 2 overlaps with x-axis, draws circular arc and ray OA meets at a point along semi arch 4, meets at b point, in like manner, draw another one circular arc and meet at c point, d point, as Fig. 4 respectively at ray OC, OD with OB;
Any point on the leading portion of the straightway 2 on chi plate 1 is overlapped with c point, attachable mechanical stage plate 1 also makes the semi arch terminal 6 on chi plate 1 drop in longitudinal axis y-axis, semi arch starting point 3 drops on x-axis, now circle center hole 5 must be positioned on circular arc, the position of circle center hole 5 is one of them trisection point E of ∠ AOB, as Fig. 5;
On the leading portion of the straightway 2 in like manner just on chi plate 1, any point overlaps with d point, attachable mechanical stage plate 1 also makes the semi arch terminal 6 on chi plate 1 drop in longitudinal axis y-axis, now circle center hole 5 must be positioned on circular arc, and the position of circle center hole 5 is another trisection point F of ∠ AOB, as Fig. 6;
Connect OE, OF respectively and namely realize the bad angle ∠ AOB of trisection one, as Fig. 7.
For any one reflex angle ∠ AOB, trisection ray OC and OD of the bad angle ∠ AOB of its correspondence of trisection according to the method described above, take O as summit, OC is a limit, and utilize on chi plate 1 120 ° of scales 8 to draw hexagonal angle ∠ COE to OA direction, ray OE is a trisection line of reflex angle ∠ AOB, it is in like manner summit with O, OD is a limit, and utilize on chi plate 1 120 ° of scales 8 to draw hexagonal angle ∠ COF to OB direction, ray OF is another trisection line of reflex angle ∠ AOB.
For special angle, as the straight angle and round angle, utilize 60 ° of scales 7 on chi plate 1 and 120 ° of scales 8 by its trisection respectively.
Claims (3)
1. an instrument for Optional-angle trisecting, is characterized in that, the straightway of the circular hole by the hollow out semi-circular arc on transparent plane meter plate, chi plate, circular arc circle centre position and two end points through semi-circular arc forms.
2. the instrument of a kind of Optional-angle trisecting according to claim 1, is characterized in that, 60 ° of described semi-circular arc and 120 ° of two places indicate scale.
3. the instrument of a kind of Optional-angle trisecting according to claim 1, is characterized in that, described straightway comprises section on the left of semi arch diameter segment diameter, and on the left of described diameter, the length of section is not less than semi arch radius.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420723155.3U CN204382972U (en) | 2014-11-27 | 2014-11-27 | A kind of instrument of Optional-angle trisecting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420723155.3U CN204382972U (en) | 2014-11-27 | 2014-11-27 | A kind of instrument of Optional-angle trisecting |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204382972U true CN204382972U (en) | 2015-06-10 |
Family
ID=53355721
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420723155.3U Expired - Fee Related CN204382972U (en) | 2014-11-27 | 2014-11-27 | A kind of instrument of Optional-angle trisecting |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204382972U (en) |
-
2014
- 2014-11-27 CN CN201420723155.3U patent/CN204382972U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150610 Termination date: 20191127 |