# Diédrico System: True magnitude of the line

By projecting a straight line on a plane orthogonal projection, its projection, generally, is smaller than the original measure.

Given a straight (segment bounded by two points) we want to determine its true magnitude and the angle it makes with the planes of projection.

# Metric geometry : Investment : Application to the resolution of problems and angular tangents

Investment is a transformation that can solve problems with angular conditions. It can be applied directly or used to reduce other problems addressed simplest known nature.

The different approaches with which we can deal with a problem will be studied by developing a simple classic problem of tangents.

# Metric geometry : Arco able on a segment

The ratio between the inscribed angle and the central angle in the circumference allows to obtain a locus of great importance for numerous applications in geometry metric; this is called arc locus capable.

# Metric geometry : Angles on the circumference : Central and inscribed

In metric geometry measuring two concepts on which is based its axiomatic model: measures linear and angular measurements.
The linear measurement is based on the Pythagorean theorem and the relationship between these measures in Thales.
The angular measurement from the relations expressed in a circle and with the above can describe the magnitude of geometric figures.