Demonstration of theorem which states sum of two sides of a triangle must be greater than the third side. By changing angle of sides and their lengths you can better understand the theorem.
This illustrates construction of upper half of a large ellipse to be used in a woodworking project.
Using a stick of length of major axis and a nail in the stick at distance from end for minor axis we see an illustration of how to draw the ellipse on a board.
Still a bit of work in progress, this is an illustration of using Angle of Depression often found in high school applied trigonometry programs.
You can change the height of the tower/person on the ground and distance from the person/ground and see the calculated angles of depressions.
Currently documented examples from many users of JSXGraph.