one thing to be noteworthy is that this triangle has two angles, a 60° one and a 90° one, meaning the last angle will be a 30° one, thus we can use the 30-60-90 rule.
Check the picture below.
There you go, help this helps!
This is a division problem.
6/20 = 0.3
Answer: You are paying $0.30 per ticket.