Green lines indicate additions to the file included with the Pull Request (PR), red line are those removed.  I do not think anything needs to be changed, when I run the example code I get a value of 294.28710938, which is also in line with the values calculated using other methods.  

In general if there are issues that need to be fixed in a PR before merging it is best to ask the original author to make them in his or her folk.  When they make commit and push them to GitHub the PR will be automatically updated to include them until the PR is merged.  If the original author is unable to unwilling to fix the issues, the changes can still be updated and merged without ever placing the repo in a "bad" state.  Typically in these cases I checkout the PR fork, make the needed changes, and then merge into master locally.  Pushing this to GitHub will close the PR automatically, but again the preferred method is to have the original author make the changes.