Video lesson: Circumference and Circle

Did you understand the explanation of video lesson 1? If you did not understand, write here what you did not understand, identifying at what time (minutes and seconds) of the video the doubt occurred.

Did you understand the explanation of video lesson 2? If you did not understand, write here what you did not understand, identifying at what time (minutes and seconds) of the video the doubt occurred.

Did you understand the explanation of video lesson 3? If you did not understand, write here what you did not understand, identifying at what time (minutes and seconds) of the video the doubt occurred.