Title of Invention  "A DEVICE FOR VISUAL UNDERSTANDING OF GEOMETRICAL THEOREMS". 

Abstract  This invention relates to a device for visual understanding of geometrical theorems specifically the theorems relating to parallograms, rhombus, rectangle, square, trapezium and theorems relating to parallel lines intersected by a transversal. The device is provided on a smooth supporting sheet preferably acrylic and consists of four full scales joined together with nut and bolts to form a quadrilateral and two scales joined across the diagonals of quadrilateral. A full protractor with 0 to 360°C marking is provided at the intersection of the diagonals. Four semicircular protractors are provided at each of the vertices of the quadrilateral formed by the scales. 
Full Text  FIELD OF INVENTION This invention relates to a device for visual understanding of geometrical theorems. Specifically but without implying any limitation thereto, the device of the present invention enables visual demonstration of geometrical theorems relating to parallelogram, rhombus, square, rectangle, and theorems relating to parallel lines intersected by a transversal. PRIOR ART Students at the schools are generally taught geometrical theorems without any visual teaching aid. The different theorems on circles, triangles and quadrilateral including rhombus, square, rectangle, parallelogram are orally explained by the teachers. The different theorems are proved by the teachers based on the logical reasoning and conclusion drawn from the proof of related theorems, which generally involves number of steps. It is often drudgery for the students to understand the different steps of proof of theorems based on oral teaching of the approach for proving the theorem and different reasoning steps involved in the proof of a theorem. The proof of a theorem often involves committing to memory of the different steps of theorem and also the results of the related geometrical theorems. The students have no way to visually understand a geometrical theorem and verify the result/conclusion established by a theorem. It is also an admitted fact that understanding and retention of the geometrical theorems by the students based on oral teaching is comparatively lower as compared to the teaching of the geometrical theorems based on visual teaching aids. A visual teaching aid known in the art as per US Patent No.5,7.32,4.74 comprises a disk having indicia representing 360degree compass, the disk having a first fixed leg bearing indicia in units of length and second leg having a sleeve portion which is pivotaiiy attached to the center of disk by snap grommet. A limitation of the above device that the theorems regarding Diagonals of square, rectangle, parallelogram and Rhombus can not be explained with above device. Another drawback of the above device is that manufacturing of the above device is relatively more difficult. Still another drawbacks of the above device is that the device require relatively more number of adjustments and the adjustments required are timeconsuming. OBJECTS OF PRESENT INVENTION An object of the present invention is to provide a device to aid visual understanding of geometrical theorems on quadrilateral including squares, rectangle, rhombus, parallelogram and also the theorems relating to parallel lines intersected by a transversal. STATEMENT OF INVENTION According to this invention there is provided a device for visual understandmg of geometncal theorems characterized in that the device is provided on a smooth supporting sheet which is fixed on a wooden frame with screws and wherein the device comprises of: (a) a scale fixed at one end with nut & bolt means and joined to other three full scales by nut 8s bolt means the said scales forming a quadrilateral and being rotatable around the said nut & bolt means; (b) scales having grooves at one end whereas scale having groove at one end and groove at other end, the grooves enabling to and fro movement in scales thereby enabling formation of rhombus, square, parallelogram, trapezium and rectangle as required with scales forming as sides; (c) four protractors with 0 to 180° markings, with one protractor provided at each of said nut 8B bolt means; (d) two scales of length such as 50cm, each having a groove at one end, with one end of scale being fixed at nut 8B bolt means and groove thereof passing through diagonally opposite nut 8B bolt means whereas the one end of scale is joined at bolt and groove thereof passing through diagonally opposite nut 8B bolt means the two scales having grooves around middle and passing diagonally one over the other; (e) a round protractor with 0 to 360° marking joined to the intersection of scales with nut 85 bolt means passing through a hole in the said round protractor and through the grooves. DESCRIPTION OF FIGURES The present invention will now be illustrated with an accompanying drawing which is an illustrative embodiment of the present invention and is not intended to be taken restrictively to imply any limitation on the scope of the present invention. The accompanying figure: Fig. 1: shows the construction of the device of the present invention. DESCRIPTION OF THE INVENTION WITH REFERENCE TO DRAWINGS Referring to fig. 1, the device of the present invention comprises supporting sheet having smooth surface, the material for the said supporting sheet may be plastic or metallic preferably an acrylic sheet (1). The sheet which is at least 30cm long and 30cm wide is screwed on to a wooden frame (2) with the help of number of screws like (3). A full scale (4) of 30cm is mounted horizontally on to the acrylic sheet, the edges of scale being parallel to the edges of acrylic sheet. The one end of the scale is fixed to the acrylic sheet and to the wooden board thereunder, with the help of nut & bolt means (5) passing through a hole made in the scale. The other end of the scale has a horizontal groove (6) parallel to the length of scale and running along the middle of the breadth of the scale. A groove corresponding and equal in dimension to the groove in the scale, is provided in the said acrylic sheet so that nut 8& bolt means (7) pass through the groove in acrylic sheet as well as through the groove (6) in the scale (4). The nut 85 bolt means (7) is kept loose so that it can be alided to and fro along the length of groove (6). Three full scales (8,9,10) are joined with scale (4) by nut 8B bolt means (5,7,11,12) so as to form a quadrilateral. While the one end of scale (8) is joined to the one end of scale (4) at nut 85 bolt (7), the other end of the scale (8) is joined to scale (9) by nut 85 bolt means (11). The scale (8) has also a groove (13) of about 10cm, parallel to the length of the scale. The nut 8B bolt means (11) can move to and fro along the length of this groove (13). Scale (9) has grooves (14,15) of length 6 to 10cm, with one groove (14) at one end and other groove (15) at the other end. The scale (10) has groove (16) at the upper end only. The scale (9) can be moved to and fro along the length of grooves (13) & (16) by sliding to and fro the loose nuts (11) and (12) and fixed at any required position with nuts (11) 8B (12). Scale (9) can also be moved horizontally at both the ends via the groove (14) provided at one end groove (15) provided at other end, by sliding nuts 8B bolts (11) 8B (12) along the length of scale (9). The scale (8) can also be moved to and fro along the groove (6) of scale (4) at one end and along groove (14) of scale (9) at the other end. However the scale (10) can be given angular movement around the nut (5). By angular movements and by to and fro movement and by tightening the bolts (7,11,12) at the required positions, the quadrilateral formed by the four scales (4,8,9,10) can be formed into a parallelogram, rectangle, rhombus, trapezium or a square as required. For measurement of angles, four protractors (17,18,19,20) with 0 to 180° markings are provided with one protractor being provided at each corner of the quadrilateral. These protractors can be given angular movement as desired along the nuts (5,7,11,12). A scale (21) preferably of at least 50cm length and preferably having marking on only one edge, is fixed at one end at bolt (5) and the other end of scale (21) has a groove (23) which passes through the diagonally opposite nut & bolt (11) and thus the scale (21) forms one of the diagonals of the quadrilateral. The scale (21) has also a groove (25) around the middle of the scale. Similarly there is another scale (22) having groove (24) around the middle and groove {26) at other end and the one end of the scale (22) being joined at the nut (7) and the groove (26) at the other end passing through nut (12). The scale (22) forms the other diagonal of the quadrilateral. The scales (21) 8B (22) have preferably markings only along one edge. When scales (4,8,9,10) are moved then the scales (21,22) forming diagonals also move correspondingly. The scales forming sides of quadrilateral and scales forming diagonals can be fixed at any required position by tightening the nuts and bolts (7,11,12) depending upon whether theorems are required to be demonstrated on rectangle, rhombus, square, parallelogram or parallel lines and their transversal. At the intersection of diagonals represented by scales (21) and (22), a round protractor (27) with 0 to 360° marking is provided and the center of round protractor (27) is joined to the intersection of the diagonals by a nut 8& bolt means (28). To facilitate measurement of angle subtended by one scale with respect to another scale, a distinct reference line like the line (29) is drawn at the middle of each scale. METHOD OP WORKING To illustrate the working of invention, we take an example of demonstrating that the diagonals of a rhombus are perpendicular and bisect each other, the nut & bolt means (5) (referred hereinafter as 'A*), nut & bolt means (7) (referred hereinafter as eB'), nut & bolt means (11) (referred hereinafter as *C) and nut & bolt means (12) (referred hereinafter as T)') are positioned in such a way that lengths AB, BC, CD and DA of quadrilateral ABCD are equal i.e. AB=BC=CD=DA. Formation of rhombus is further ascertained by adjusting angles ZBAD= ZBCD and ZCBA=ZCDA with the help of protractors (17,18,19,20). At this position the nuts & bolts means (7,11,12) are tightened and the zero marking of round protractor (27) is aligned with reference line of diagonal scale (22). Referring nut (28) as *0', the angles BOC, COD, BOA and AOD are measured with the help of round protractor (27). It is observed that ZBOC=ZBOA=ZAOD=ZCOD=90°. Further lengths OA, OB, OC and OD are measured with the help of diagonal scales (21) and (22). It is observed that BO=OD and AO=OC. Thereby demonstrating that diagonals of rhombus are perpendicular to each other and bisect each other. In this way different theorems relating to parallelogram, rhombus, square, rectangle and also theorems relating to parallel lines such as alternate angles, corresponding angles, vertically opposite angles etc can be demonstrated. Specifically but with out implying any limitation thereto, the following theorems can be proved with this device: (i) In a parallelogram opposite sides are equal. (ii) The opposite angles of a parallelogram are equal. (iii) The diagonals of a parallelogram bisect each other. (iv) A quadrilateral is a parallelogram if its opposite sides are equal. (v) A quadrilateral is a parallelogram if its opposite angles are equal, (vi) If the diagonals of a quadrilateral bisect each other then the quadrilateral is a parallelogram. (vii) A quadrilateral is a parallelogram if its one pair of opposite sides are equal and parallel, (viii) The diagonals of a rectangle are of equal length, (ix) The diagonals of a rhombus are perpendicular to each other and bisect each other. (x) The diagonals of a square are equal and perpendicular to each other, (xi) If the diagonals of parallelogram are equal then it is called as a rectangle, (xii) If the diagonals of a parallelogram are perpendicular then it is a rhombus, (xiii) If in a parallelogram the diagonals are equal and perpendicular than it is a square. (xiv) If two lines intersect then vertically opposite angles are equal, (xv) If a straight line stands on another straight line then the sum of adjacent angles so formed is equal to 180. (xvi) If a transversal intersects two parallel lines, then each pair of alternate interior angles are equal, (xvii) If a transversal intersects two lines, in such a way that a pair of alternate interior angles are equal then the two lines are parallel, (xviii) If a transversal intersects two parallel lines then the interior angles are supplementary, (xix) If a transversal intersects two lines in such a way that a pair of consecutive interior angles are supplementary, then the two lines are parallel. (xx) If a transversal intersects two parallel lines then each pair of corresponding angles are equal. It is to be noted that present invention is susceptible to modifications changes and adaptations by those skilled in the art. Such, variant embodiments incorporating the concepts and features of the present invention, are intended to be within the scope of the present invention, which is further set forth under the following claims: WE CLAIM: 1. A device for visual understanding of geometrical theorems characterized in that the device is provided on a smooth supporting sheet (1) which is fixed on a wooden frame (2) with screws (3) and wherein the device comprises of: (a) a scale (4) fixed at one end with nut & bolt means (5) and joined to other three full scales (8, 9, 10) by nut & bolt means (7, 11, 12), the said scales forming a quadrilateral and being rotatable around the said nut & bolt means (5, 7, 11, 12); (b) scales (4, 8, 10) having grooves (6, 13, 16) at one end whereas scale (9) having groove (14) at one end and groove (15) at other end, the grooves enabling to and fro movement in scales (8, 9, 10) thereby enabling formation of rhombus, square, parallelogram, trapezium and rectangle as required with scales (4, 8, 9, 10) forming as sides; (c) four protractors (17, 18, 19, 20) with 0 to 180° markings, with one protractor provided at each of said nut & bolt means (5, 7, 11, 12); (d) two scales (21, 22) of length such as 50cm, each having a groove (23, 26) at one end, with one end of scale (21) being fixed at nut & bolt means (5) and groove (23) thereof passing through diagonally opposite nut & bolt means (11) whereas the one end of scale (22) is joined at bolt (7) and groove (26) thereof passing through diagonally opposite nut & bolt means (12), the two scales having grooves (24, 25) around middle and passing diagonally one over the other; (e) a round protractor (27) with 0 to 360° marking joined to the intersection of scales (21) & (22), with nut & bolt means (28) passing through a hole in the said round protractor and through the grooves (24) & (25). 2. A device as claimed in claim 1 wherein the grooves (6, 13, 14, 15, 16, 23, 24, 25, 26) have lengths preferably between 6 to 10cm. 3. A device as claimed in claim 1 wherein the diagonal scales (21, 22) have preferably markings along one edge. 4. A device as claimed in claim 1 wherein the material for the said smooth supporting sheet (1) is selected from plastic, metal preferably acrylic. 5. A device for visual understanding of geometrical theorems on parallel lines and quadrilaterals comprising square, rectangle, rhombus, parallelogram, as substantially described and illustrated herein. 

1485del2003complete specification granted.pdf
1485DEL2003CorrespondenceOthers (06112009).pdf
1485DEL2003CorrespondenceOthers(25062009).pdf
1485del2003correspondenceothers.pdf
1485DEL2003CorrespondencePO.pdf
1485del2003description (complete).pdf
Patent Number  237373  

Indian Patent Application Number  1485/DEL/2003  
PG Journal Number  52/2009  
Publication Date  25Dec2009  
Grant Date  17Dec2009  
Date of Filing  28Nov2003  
Name of Patentee  GOVERNMENT HIGH SCHOOL METHAN  
Applicant Address  THE. PHAGWARA, DISTT. KAPURTHALA, PUNJAB, INDIA.  
Inventors:


PCT International Classification Number  B43L 007/10  
PCT International Application Number  N/A  
PCT International Filing date  
PCT Conventions:
