세개의 구멍을 모두 통과? / Go through the three holes?퀴즈 영상2020.05.02.2024.02.15. 방철린(불휘기픈)https://www.youtube.com/watch?v=Pr_UxCsXMDY
정사면체를 자르면?/Cut a regular tetrahedron, what happen?퀴즈 영상2020.05.02.2024.02.15. 방철린(불휘기픈)https://www.youtube.com/watch?v=6jokCp43_HE
어떻게 생겼을까? / Can you complete?퀴즈 영상2020.05.02.2024.02.15. 방철린(불휘기픈)https://www.youtube.com/watch?v=QxCCSMnxlnA&t=45s
나갈 수가 있어요? / Can they get out?퀴즈 영상2020.05.02.2024.02.15. 방철린(불휘기픈)https://www.youtube.com/watch?v=_WtlPYxufv8&t=11s
넷으로 나눈다?/Divide into 4?퀴즈 영상2020.05.02.2024.02.15. 방철린(불휘기픈)https://www.youtube.com/watch?v=YLGYWXtIPj0&t=7s
