{"type":"rich","version":"1.0","title":"geometric (hyperbola-based) definition of e (Euler's number)","html":"<iframe src=\"https://www.desmos.com/calculator/h9cjgq3xul?embed\" width=\"500px\" height=\"500px\" style=\"border: 1px solid #ccc\" frameborder=0></iframe>","width":500,"height":500}