## GeoGebra Essentials 5 – The Compass Tool and the SSS Congruence

This is the fifth tutorial in the GeoGebra Essentials Series. If you are not familiar with GeoGebra, you may want to read the Introduction to GeoGebra post and prior tutorials. They contain the pre-requisites of this tutorial.

In the tutorial below, menu commands, located in the menu bar, are in brown bold text, and submenus are denoted by the > symbol. For example, Options>Labeling> New Points Only means, click the Options menu, choose Labeling from the list, then select New Points Only. The tool texts are colored orange. For example, New Point means the new point tool.

In this tutorial, we will mimic compass and straightedge construction using GeoGebra’s Compass tool, Segment and Ray tools. We use the concept of the SSS congruence1 to construct a triangle congruent to a given triangle. » 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

## GeoGebra Tutorial 21 – Spreadsheet and Similarity

This is the 21st 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  investigate what happens if we multiply the coordinates of the vertices of a triangle with a constant.  First, we  plot three points that will be the vertices of a triangle, and then draw the triangle using the Polygon tool. Next, we will construct slider k, and see what happens if we multiply the coordinates (x1,y1), (x2,y2) and (x3,y3) of the vertices of the triangle by k. We also explore the relationship between the original triangle and the triangles  with coordinates (kx1,ky1), (kx2,ky2) and (kx3,ky3).

You can view the output of this tutorial here.

Step-by-Step Instructions