How to make a half-rounded edge kitchen counter

These are some links to a thread and videos that may be helpful
http://forums.thesims.com/en_US/discussion/comment/12553844/#Comment_12553844
http://www.simified.com/the-sims-4/tutorials/kitchen-cabinets-islands/
https://m.youtube.com/watch?list=PLm7eMVoztWXdOekmv6rH0cWw842Zf5vm-&v=AlOTEijVVTs