The Geometer's Sketchpad is a commercial

interactive geometry software Interactive geometry software (IGS) or dynamic geometry environments (DGEs) are computer programs which allow one to create and then manipulate geometric constructions, primarily in plane geometry. In most IGS, one starts construction by putting a ...

program for exploring

Euclidean geometry Euclidean geometry is a mathematical system attributed to ancient Greek mathematics, Greek mathematician Euclid, which he described in his textbook on geometry: the ''Euclid's Elements, Elements''. Euclid's approach consists in assuming a small ...

algebra Algebra () is one of the broad areas of mathematics. Roughly speaking, algebra is the study of mathematical symbols and the rules for manipulating these symbols in formulas; it is a unifying thread of almost all of mathematics. Elementary a ...

calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...

, and other areas of

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

. It was created as part of the

NSF NSF may stand for: Political organizations *National Socialist Front, a Swedish National Socialist party *NS-Frauenschaft, the women's wing of the former German Nazi party *National Students Federation, a leftist Pakistani students' political gr ...

-funded Visual Geometry Project led by Eugene Klotz and

Doris Schattschneider Doris J. Schattschneider (née Wood) is an American mathematician, a retired professor of mathematics at Moravian College. She is known for writing about tessellations and about the art of M. C. Escher,.. for helping Martin Gardner validate and p ...

from 1986 to 1991 at

Swarthmore College Swarthmore College ( , ) is a Private college, private Liberal arts colleges in the United States, liberal arts college in Swarthmore, Pennsylvania. Founded in 1864, with its first classes held in 1869, Swarthmore is one of the earliest coeduca ...

. Nicholas Jackiw, a student at the time, was the original designer and programmer of the software, and inventor of its trademarked "

Dynamic Geometry Interactive geometry software (IGS) or dynamic geometry environments (DGEs) are computer programs which allow one to create and then manipulate geometric constructions, primarily in plane geometry. In most IGS, one starts construction by putting a ...

" approach; he later moved to

Key Curriculum Press McGraw Hill is an American educational publishing company and one of the "big three" educational publishers that publishes educational content, software, and services for pre-K through postgraduate education. The company also publishes referenc ...

, KCP Technologies, and McGraw-Hill Education to continue ongoing design and implementation of the software over multiple major releases and hardware platforms. Present versions run

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

and

Mac OS 8 Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It includes the largest overhaul of the classic Mac OS experience since the release of System 7, approximately six years before. It places a greater emphasis on ...

. It also runs on

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

under

Wine Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are m ...

with a few bugs. There was also a version developed for the

TI-89 The TI-89 and the TI-89 Titanium are graphing calculators developed by Texas Instruments (TI). They are differentiated from most other TI graphing calculators by their computer algebra system, which allows symbolic manipulation of algeb ...

and

TI-92 The TI-92 series of graphing calculators are a line of calculators produced by Texas Instruments. They include: the TI-92 (1995), the TI-92 II (1996), the TI-92 Plus (1998, 1999) and the Voyage 200 (2002). The design of these relatively large ...

series of Calculators. In June 2019 McGraw-Hill announced they will no longer sell new licenses. Nonetheless,
new (2021) 64-bit version of Mac Sketchpad
that is compatible with the new Apple M1 silicon chips is available as part of an ongoing beta test.

Features

The Geometer's Sketchpad includes the traditional Euclidean tools of classical geometric constructions. It also can perform transformations (translations, rotations, reflections, dilations) of geometric figures drawn or constructed on screen. It is far more than a construction or transformation tool, however. It can manipulate constructed objects "dynamically" by stretching or dragging while maintaining all constraints of the construction so that a seemingly infinite number of cases of a constructed figure can be viewed. Thus it is a natural tool for making or testing conjectures about geometric figures. Its accurate drawings of geometric figures make it a useful tool for illustrating mathematical articles for publication. If a figure (such as the

pentadecagon In geometry, a pentadecagon or pentakaidecagon or 15-gon is a fifteen-sided polygon. Regular pentadecagon A '' regular pentadecagon'' is represented by Schläfli symbol . A regular pentadecagon has interior angles of 156 °, and with a side l ...

) can be constructed with the compass and straightedge method, it can also be constructed in the program. The program allows "cheat" transformations to create figures impossible to construct under the compass and straightedge rules (such as the regular

nonagon In geometry, a nonagon () or enneagon () is a nine-sided polygon or 9-gon. The name ''nonagon'' is a prefix hybrid formation, from Latin (''nonus'', "ninth" + ''gonon''), used equivalently, attested already in the 16th century in French ''nonogo ...

). Objects can be animated. The program allows the creation of numerous objects which can be measured, and potentially used to solve hard math problems. The program allows the determination of the

midpoint In geometry, the midpoint is the middle point of a line segment. It is equidistant from both endpoints, and it is the centroid both of the segment and of the endpoints. It bisects the segment. Formula The midpoint of a segment in ''n''-dimens ...

s and midsegments of objects. The Geometer's Sketchpad can measure lengths of segments, measures of

angle In Euclidean geometry, an angle is the figure formed by two Ray (geometry), rays, called the ''Side (plane geometry), sides'' of the angle, sharing a common endpoint, called the ''vertex (geometry), vertex'' of the angle. Angles formed by two ...

area Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape A shape or figure is a graphics, graphical representation of an obje ...

perimeter A perimeter is a closed path that encompasses, surrounds, or outlines either a two dimensional shape or a one-dimensional length. The perimeter of a circle or an ellipse is called its circumference. Calculating the perimeter has several pract ...

, etc. Some of the tools include a construct function, which allows the user to create objects in relation to selected objects. The transform function allows the user to create points in relation to objects, which include distance, angle, ratio, and others.Geometry Turned On: ''Dynamic Software in Learning, Teaching, and Research'', James King and Doris Schatschneider, eds., Math. Assoc. of Amer., 1997.

Web Sketchpad

Built on the foundation of The Geometer's Sketchpad
Web Sketchpad
(WSP) began as part of the NSF DRK-12 funde
Dynamic Number project
WSP removes distracting interfaces—it has no menus, displays no dialog boxes, and does not require users to “select” objects to apply commands to them. Three noteworthy characteristics of Web Sketchpad's tools are the following: Web Sketchpad's tools are immediately visible. When a user taps a tool icon, all the objects produced by the tool are immediately visible, foregrounded in the sketch and awaiting the user's decision as to how to integrate these objects into the sketch. In contrast, other dynamic mathematics software often leaves students unable to predict the effects of their next action. Web Sketchpad's tools are targeted. Activities include only those tools necessary for the task at hand, reducing software complexity. A focused set of tools also the activity designer to create instrumented fields of promoted action where the presence of particular tools encourages teachers and students to adopt these tools as frames of action and reference, channeling them to think about problems in ways they otherwise might not. Web Sketchpad's tools are customizable. The set of WSP tools is theoretically unlimited. A teacher can craft new tools based on the mathematical and pedagogical needs of a lesson without the traditional limits of a fixed set of generic tools.

References

External links

*
Sketchpad Repository

Web Sketchpad
{{DEFAULTSORT:Geometer's Sketchpad Interactive geometry software

Features

Web Sketchpad

See also

References

Further reading

External links