Thanks to Rex Boggs, Rockhampton Grammar School, Australia (http://bit.ly/rexboggs) for help with the English translation.

Constructing the Perpendicular Bisector of a Line Segment

The perpendicular bisector of a line segment is the line which is
perpendicular to a given line segment and which divides it into two
equal line segments.
How to construct the perpendicular bisector of a line segment (by using
just a straightedge and compass, without a triangle)?
Find the answer in this video.
Construction on paper.
Video without words.

Dividing line segments into equal parts - on paper

In this video you will learn how to divide a line segment into equal
parts, without measuring.
Drawing on paper.

Dividing line segments into equal parts - in GeoGebra

For given line segment and slider n (whose value we can
change) we should divide the line segment into n equal parts.
How to do it, watch in this video.
Drawing in GeoGebra.

Dividing a Line Segment in a Given Ratio - on Paper

In this video you will learn how to divide a line segment in a given
ratio, without measuring.
Drawing on paper.

Dividing a Line Segment in a Given Ratio - in GeoGebra

In this video you will learn how to divide a line segment in a given
ratio, without measuring.
Drawing in GeoGebra.