## GeoGebra Essentials 4 – Angles, Lengths and Object Properties

This is the fourth tutorial in the GeoGebra Essentials Series. If you are not familiar with GeoGebra, you may want to read the Introduction to GeoGebra post and earlier GeoGebra tutorials in this series. It contains the pre-requisite materials for 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 GeoGebra tools are denoted by orange texts. For example, New Point means the new point tool.

In this tutorial, we use GeoGebra to investigate the relationship between the interior angles of a triangle and the lengths of its sides. We also learn two new tools – the Angle and the Distance or Length tool. In addition, we discuss how to change the basic properties (color, width, and style) of mathematical objects. The output of our tutorial is shown above. » Read more

## GeoGebra Tutorial 29 – Animation, Roses and Radian

This is the 29th 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 learn the concept of radian.  One radian is equal to the subtended angle of the arc with the same length as the circle’s radius. In this tutorial, we rotate radius AB’ about point A, the center of the circle. As the point rotates, point C goes back and forth from A to B’ at the same speed. The path of point C forms petals (see red petals in the figures below). The ratio of the maximum number of petals formed and the number of rotations is a good approximation of $\pi$ Instructions

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