Accessibility for totally blind users

I’m writing this request because I am finding this app mostly very helpful. There is just one part of the app so far that I am struggling with. First off, I want to praise those Who developed and our continuing to work on the Khan Academy app. I am finding that most of the questions on the app are very accessible. I appreciate this because it gives me the chance to teach myself math which I am trying to learn to get my high school education. However, I am struggling with the pictures. The videos that show me pictures are hard to understand because obviously I can’t see them. A possible suggestion could be maybe the teachers could be a little more descriptive. By saying how long each object is for example. In the practice activities, it asked me to order the lines from shortest to longest. I am not able to do this because my screen reader will not tell me which is which. I understand that problems like this can be difficult to solve. I’m hoping however, that somehow we could find a solution to this problem so that I may continue to study, and other blind users can as well. Thank you so much.