Title of Invention

"AN IMPROVED DEVICE FOR VISUAL UNDERSTANDING OF GEOMETRICAL THEOREMS"

Abstract

This invention relates to a device for visual understanding of geometrical theorems, specifically the theorems relating tangents to circle, chords, cyclic quadrilateral and triangle. The device is mounted on a metal or plastic sheet preferably acrylic sheet, and comprises a circle drawn/made on the acrylic sheet, a round protector (5), two scales (20,21) joined at one end by nut and bolt means (52) and other end of scale (21) having slot (23) and is capable of sliding to and fro along the nut and bolt means (12) and scale (20) is capable of sliding to and fro along the slot (22) passing over nut and bolt means (17). Five semicircular protractors being provided along the circumference of circle and two novel inverted T-shaped scale-cum-protractor instruments (28,29) are provided.

Full Text

FIELD OF INVENTION This invention relates to an improved device for visual understanding of geometrical theorems. Specifically, but without implying any limitation thereto, the device enables visual understanding of the theorems relating to tangents to a circle, chords, cyclic quadrilateral and triangle. PRIOR ART Students at the schools are generally taught geometrical theorems without any visual teaching aid. The different theorems on triangles, quadrilateral and circle are orally explained by the teachers. The different theorems are proved by the teachers based on the conclusion drawn from the proof of related theorems. The proof of any theorem generally involves number of steps. It is often drudgery for the students to understand the proof of theorems based on oral teaching of the approach, and different reasoning steps involved in the proof of a theorem. The proof of a theorem often involves committing to memory of the results of the related geometrical theorems. The students have also no way to see for themselves visually the relationship between different attributes of a geometrical figure. A visual teaching aid known in the art as per US Patent No. 5, 732, 474 comprises a disk having indicia representing 360 degree compass, the •disk having a first fixed leg bearing indicia in units of length and second leg having a sleeve portion which is pivotally attached to the center of disk by snap grommet, A limitation of the above device is that theorems regarding tangents to a circle cannot be explained with above device. Another drawback of the above device is that the manufacturing process of the above device is relatively more difficult. Still another drawback of the above device is that the device requires relatively more number of adjustments and the adjustments are relatively more time-consuming. OBJECTS OF PRESENT INVENTION The primary object of the present invention is to provide a device for visual understanding of geometrical theorems. STATEMENT OF INVENTION According to this invention there is provided an improved device for visual understanding of geometrical theorems, provided on a smooth supporting sheet fixed to a wooden frame with screws wherein the said device comprises of:- (a) said supporting sheet with a circle thereon provided with atleast three slots along the circumference of the circle and atleast two reference lines; (b) five semi-circular protractors, provided along the circumference of the circle by nuts & bolts (as shown in fig. 1) wherein the nut and bolt means are movable in the respective slots along the circumference of circle; (c) a round protractor provided at the center 'O' of circle b, means of nut & bolts mean; (d) two scales having slots at one end and joined to each other at the other and at point 'C' by nut & bolt means and protractor being provided at this end with zero of the protractor being fixed along the reference line of one of the scale by means of nut & bolt (as shown in fig, 1); (e) two inverted T-shaped scale-cum protractor instruments having marking on vertical parts as well as on horizontal part thereof and an integrated quadrant protractor at the intersection of vertical and horizontal part (as shown in fig. 2), with scale-cum protractor instrument being provided with nut. 8 & bolt passing through slots having groove ai the upper end of the vertical part; WE CLAIM: 1 An improved device for visual understanding of geometrical theorams, provided on a smooth supporting sheet (1) fixed to wooden frame (2) with screws (3) wherein the said device comprises of:- (a)said supporting sheet (1) with a circle thereon provided wito atleast three slots (7, 8. 9) along the circumference of the circle; and atleast two reference lines (50, 41); (b) five semi-circular protractors (10, 11, 14, 1.5, 18), provided along the circumference of the circle, by nuts & bolts (13, i, , 16 17, 19) (as shown in fig. 1) wherein the nut and bolt means (12, 16, 1.7) are movable in the respective slots (9, 7, 8) along the circumference of circle; (c) a round protractor (5) provided at the center 'O' of circle by means of nut. & bolt means (6); (d) (wo scales (20,21) having slots (22,23) at one end and. joined to each other at the other and at point 'C' by nut & bolt means (52) and a protractor (24) being provided at this end (22) with zero of the protractor being fixed along the reference line of one of the scale by means of nut & bolt (25) (as shown in fig. 1): (e) two inverted T-shaped scale-cum protractor instruments (28,29) having marking on vertical parts as well as on horizontal part thereof and an integrated qeadrant protractor at the intersection of vertical and horizontal part thereof (as shown n fig. 2), with scale-cum protractor instrument (29) being provided with nut. & bolt (13) and (17) passing through slots (34,36) having a groove (38,49) respectively at the upper one of the vertical part; (f) at least two stretchable members like rubber bands being provided to form cyclic triangle, quadrilateral, polygons etc 2 An improved device as claimed in claim 1 wherein the scales (20,21) have length such as 40cm An improved device as claimed in claim 1 wherein each of the inverted T-shaped scale-cum-protractor instrument (28,29) have scale marking for length measurement from 0 to 15cm on the vertical part as well as on each horizontal part, on either side of the vertical part. 4. An improved device as claimed in claim 1 wherein the material of said supporting sheet (1) is selected from plastic/metal preferable acrylic. 5 An improved device as claimed in claim I wherein the said protractors are movable along the slots as well as along their axis, 6. An improved device as claimed in claim 1 wherein the said round protractor (5) is rotatable around its exis and can be fixed at desired position with a nut & boll: means (6). 7. An improved device as claimed in claim 1 wherein the scales (20,21) and also inverted T-shaped scale-cum-potractor instruments (28,29) have preferably markings only on one edge, the other edge of the scale being transparent and blank without any marking. 8. An improved device for visual understanding of geometrical theorems as substantially herein described and illustrated.

Documents:

1484-del-2003-abstract.pdf

1484-del-2003-claims.pdf

1484-DEL-2003-Correspondence-Others (06-11-2009).pdf

1484-DEL-2003-Correspondence-Others-(25-06-2009).pdf

1484-del-2003-correspondence-others.pdf

1484-del-2003-correspondence-po.pdf

1484-del-2003-description (complete).pdf

1484-del-2003-drawings.pdf

1484-del-2003-form-1.pdf

1484-del-2003-form-19.pdf

1484-del-2003-form-2.pdf

1484-del-2003-pa.pdf