I saw this video on YouTube in which two balls slide down on different inclines.

The part which confused me was the one at 2:00 seconds. I couldn't understand why the two balls hit the bottom at the same time or why the two pendulums released from different angles have the same time period ?

If we drop two balls from different heights they do take different time to come down . But here they are coming simultaneously.

One reason which I thought could be that the velocity gained by the balls is proportional to length of the incline but I am not sure and couldn't digest it .

Can someone give me the reason for that ?