Investigate the effect of oxygen deprivation on brain function and test the changes in mental abilities climbers experience as they climb to ever-higher altitudes, in this virtual experiment.

Technical journal's articles discuss issues in training and nutrition, with such topics as altitude training and psychological activity.

This site from MathWorld.com offers extensive information on right triangles. The site contains information on numerous characteristics of right triangles, including constructing similar inscribed triangles, altitudes, Pythagorean...

MathWorld goes into detail about equilateral triangles at this site. Use this site to find out how to construct an equilateral triangle using a compass and straight edge. Learn about the altitude of such triangles, and the rationality of...

Find the gradient, equations and intersections of medians, altitudes and perpendicular bisectors using our knowledge of the mid-point as well as parallel and perpendicular lines.

[Free Registration/Login may be required to access all resource tools.] An overview of altitudes and geometric mean is provided in this study guide.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.

A brief biography and discussion of Aristarchus' theories provided here.

In this skill activity, students can use the Constructions Tools Menu in Cabri Jr. to contruct a parallelogram. They will also construct an altitude, an angle bisector and a median of a triangle.

In Spanish. Interactive activities dealing with the concept of angle bisector, median and altitude of a triangle. A description of the circumcenter and centroid are given along with a visual representation. [Requires Java.]

You will find an interactive activity to review the following concepts: altitude, median, angle bisector and points of concurrency in triangles. Five different interactive quizzes are also provided to test your knowledge.

In this activity, students use the Cabri Jr. tools to draw altitudes in a triangle. They construct a line perpendicular to a given line and through a given point. [Requires Adobe Reader.]