## New GeoGebra Tutorials

I have written more than 30 GeoGebra tutorials for the past year, but I felt that it was written sloppily. From now on, we will refer to them as the GeoGebra Intermediate Tutorial Series. Honestly, I wrote those tutorials without thinking of the order and length.  In fact, they can be considered as stand-alone tutorials.  I have also never bothered to write about the technical explanations behind the constructions. For instance, I did not explain the difference between free and dependent objects; I never taught how to use construction protocols and many others. For this reason, I have decided to create another tutorial series – the GeoGebra Essentials Tutorial Series. GeoGebra Essentials will cater those who have zero or very little knowledge about GeoGebra. The construction steps will be shorter — more or less 10 steps per tutorial. Unlike in previous tutorials, we will  discuss the technical and mathematical ideas behind the constructions. We will probably do some “less serious” constructions  just like the one shown above – constructions which will let us appreciate the non-mathematics part of GeoGebra (click figure above to view animation).

For intermediate GeoGebra users, we will also be starting the GeoGebra Advanced Tutorial Series. We will learn basic HTML, Javascript coding, tools customization, and website embedding. We will also have some advanced mathematics constructions.

## 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

## 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