I am preparing a study ''On the enrichment of the non-Euclidean geometries subject for high school students,'' and I am ready to get your ideas and advice on this. Many thanks...
A recent account is "ICT and Liminal Performative Space for Hyperbolic Geometry’s Teaching" by Panagita Kotarinou and Charoula Stathpolou. April 2017.
For spherical geometry try "Characterizing student mathematics teachers’ levels of understanding in spherical geometry" Bulent Guven & Adnan Baki . 2010
"Conceptual Change in Non-Euclidean Mathematics" by Asmuth, J and Rips, L proposes two different approaches learning non-euclidean geometry. 2009
Although rather old but still useful "Supporting the evolution of mathematical meaning: The case of Non-euclidean Geometry." Noss, R and Stevenson, I. J. (1999) International Journal of Computers for Mathematics Learning. 3 (3):229-254
Two approaches to non-euclidean geometries using "closing the triangle" and "finding asymptoes" are in "Constructing Curvature:
The Iterative Design of a Computer-Based Microworld for Non-Euclidean Geometry" (1996) Stevenson, I.J.
There are several others if you are interested. It would be very interesting to hear what approach you take and "what works"
Thank you very much for your contribution and opinions. Yes, I feel that we need to make more efforts to convey this significant subject to high school students, and I believe that excellent results will be achieved if we all work together on this.