Problem solved by updating Firefox to v. 38.0.1

1. Közösség
2. Study Group
3. Geometry task Defining reflections interactive

I've watched some worked examples videos and in them there is the original line or figure in blue and another one in gray. When I do my exercises I'm not able to see the one in gray. Pls I need so...

1. Közösség
2. Study Group
3. Geometry task Defining reflections interactive

here is the link: https://www.khanacademy.org/mission/geometry/task/5893250978283520

1. Közösség
2. Study Group
3. Geometry task Defining reflections interactive