## GeoGebra Essentials 2 – Constructing a Rectangle

This is the second tutorial in the GeoGebra Essentials Series. If this is your first time to use GeoGebra, it is important that you read the Introduction to GeoGebra post. It is also important to read the GeoGebra Essentials 1. This tutorial is just a repeat of the GeoGebra Basic Construction 5, but I have put a more thorough discussion on free, semi-free and independent objects.

In the tutorial below, menu commands, located in the menu bar, are in green bold text, and the submenus are denoted by the > symbol. For example, Options>Labeling>New Points Only means you have to click the Options menu, choose Labeling from the list, then New Points Only. The tool texts are colored light red. For example, New Point means, the New Point tool.

In this tutorial, we  create a rectangle using the segment tools, the parallel line tool, and perpendicular line tool.  We learn how to measure the length of segments and angles. The output is of this tutorial is shown below. » Read more

## GeoGebra Tutorial 27 – Animation and Epicycle

This is the 27th tutorial of the GeoGebra Intermediate Tutorial Series. If this is your first time to use GeoGebra, you might want to read the GeoGebra Essentials Series.

In this tutorial, we rotate a circle about the center of another circle tangent to it using the animation feature of GeoGebra. Along the rotating circle, we will also rotate a point on its circumference about its center (see red point in the diagram). The path of this point is called the epicycloid.

If you want to follow this tutorial step-by-step, you can open the GeoGebra window in your browser by clicking here.  You can view the output of this tutorial here. » Read more

## GeoGebra Tutorial 31 – Paper Folding Simulation

This is the 31st GeoGebra Tutorial of the GeoGebra Intermediate Tutorial Series. If this is your first time to use GeoGebra, you might want to read the GeoGebra Essentials Series.

In this tutorial, we are going to use GeoGebra to simulate paper folding. We will represent a rectangular piece of paper with corners ABCD and drag the upper right corner (vertex B) anywhere inside the rectangle.

We will use a Point on Object, a which is only available in GeoGebra 4.0 Beta Release, which can be downloaded here. As an alternative, the Point in region tool can be replaced by the New point tool as an alternative in lower versions (see details in the step-by-step instructions). » Read more

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