National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Hyperbolic Geometry
Dr. Math, responds to a question fro a nineth grade stduent who wants to understand hyperbolic geometry. The Dr. uses descriptive analogies in attempts to unravel why triangles in hyperbolic geometry have less than 180 degrees in them.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: When Is a Slope 0 or Undefined?
At this site Dr. Math gives a discussion on the slopes of lines. The Dr. gives an analogy between the slope of a line and walking up and down hills. The Dr. explores the concept of undefined and zero slopes through his response to a...