National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: High School Archive on Geometry
This site is an archive of questions posed by students and the general public about geometry which are responded to by "Dr. Math."
National Council of Teachers of Mathematics
The Math Forum: Measuring Distances Triangulation
Lesson plan which details how to have students determine the distance to an object by sighting it from two different locations and knowing the distance between these locations. As an advanced alternative, trigonometry can be used to...