# 101 Project Ideas

*101 Project Ideas for The Geometer's Sketchpad* is a booklet from McGraw-Hill Education that's full of exciting project ideas for use in the classroom or at home. The projects are for users with varying degrees of Sketchpad experience and cover a wide range of subject areas (art/animation, triangles, real-world modeling, calculus, transformations and tessellations, trigonometry, fractals, and many more). It's available as a free download (PDF).

## 16 Example Projects

Click links in the project sections below to download example "solution sketches" to sample projects chosen from *101 Project Ideas for The Geometer's Sketchpad.* These sketches are designed for both Macintosh and Windows compatibility. Alternately, you can access all these 16 projects in this single Sketchpad document.

## Project 4A two-dimensional template for folding a three-dimensional solid is called a net. Construct nets for each of the five Platonic Solids, complete with folding tabs. (A net for a tetrahedron is shown at right.) Then print out your nets and build the solids! Download: 04PlatonicNets.gsp |

## Project 7The logo for the Download: 07IMPLogo.gsp |

## Project 9Create two or more figures using segments, arcs, circles, or whatever. The figures can be letters, geometric figures, or even caricaturized faces. Now, using Movement buttons (or, for more control and sophistication, a slider controlling a dilation from one state to the other), set things up so that one figure "morphs" into the other. Download: 09FaceMorph.gsp |

## Project 12Create a sketch that shows the graph of a general cubic function and the graphs of its first and second derivatives. Sliders should control the parameters for the original function, and as they are dragged all three graphs should change accordingly. Download: 12Derivatives.gsp |

## Project 15Construct a circle and an inscribed angle. Measure the angle and the arc it intercepts. Animate the vertex of the inscribed angle to demonstrate that every inscribed angle that intercepts this arc has the same measure. Download: 15InscribedAngle.gsp |

## Project 26If you've read the book Download: 26Dragon.gsp |

## Project 33Make a sketch that graphs a parabola in standard form
The vertex of the parabola Download: 33_34Parabola.gsp |

## Project 36Explore the polar curves Download: 36PolarGrapher.gsp |

## Project 51Construct a quadrilateral so that the only property it must have is that its diagonals are the same length as each other. What special kinds of quadrilateral could this shape be? Download: 51EqualDiags.gsp |

## Project 57In 1956, the famous philosopher Ludwig Wittgenstein proposed a thought experiment that can be paraphrased as follows:
Model this situation in Sketchpad, and then investigate how your results depend on the size of the circular track, the length of the rod, and the location of the pivot point. Download: 57Wittgenstein.gsp |

## Project 64When the top-left corner of a piece of paper is folded down to touch the bottom side of the paper, a triangle is formed in the lower-left corner, as shown at left. Model this situation in Sketchpad. (The most challenging thing is for there to be a smooth transition between different states as the point is dragged!) Now use the sketch to determine what fold angle produces the maximum area of the lower-left triangle. Further challenge: Your sketch probably falls apart when the point is dragged too close to the lower-right corner. Extend your sketch to show (and smoothly transition into) this third possible state. Can you construct a sketch in which the corner point can be dragged all the way around the edge of the piece of paper? Download: 64PaperFolding.gsp |

## Project 73Explore the so-called Lissajou curves, namely the graphs of the parametric equations Download: 73Lissajou.gsp |

## Project 78Demonstrate two different ways to tile the plane with copies of any arbitrary triangle. Download: 78TriangularTilings.gsp |

## Project 90Create a sketch that demonstrates why it is that Side-Side-Angle (SSA) is not a congruence postulate. Download: 90SSA.gsp |

## Project 101Create an animation that traces out a sine wave. Download: 101SineTracer.gsp |

## Download All 16 SamplesYou may also download all sixteen of the sample projects at once as a single Sketchpad document for both Windows and Macintosh platforms. Download: 101ProjectExamples.gsp |