Kepler and orbit of mars

[Nova12]

Hello,

i have a presentation for astronomy and I need to understand how Kepler received to find the elliptical orbit of mars. Therefore I use his book Astronomia Nova and due to its hard to comprehend its scientific language, additionally  I use this website too: New Astronomy

Well, I have difficulties with understand two main aspects:
First; In Chapter 51 of Astronomia Nova, Kepler determines the distance between Mars and sun. From that he corrects his hypothesis of chapter 40. (Chapter 56)
Picture

After that in Chapter 58 is rejects his hypothesis he made in chapter 56. What was the problem? Actually the distances were correct but were the angles wrong? Is that the case?

If yes, how can the distances be correct but not the angles? Can anyone tell me the idea behind chapter 56 to 58?

Second; In Chapter 40, kepler suggests a model for the orbit of mars. there are also distances from sun to mars. But in Chapter 51 he calculates distances from Mars to Sun again and then he prefers another orbit. Whats the difference between Chapter 40 and 51 with the distances? 

Due to english is not my first language, maybe i miss some important detail.

Thanks

[RT65CB-SWL]

Hi 'Nova12' and welcome to SGL. 

I cannot help with your question; but thank you for the link. I have just downloaded the .zip file. 

[JoeP]

From what I understand, when Kepler transfered his model to an ellipse, he placed mars at the wrong point on the ellipse. This caused the error he saw. I'm not sure about your second question - what makes you think he's using a different model?