A person stands in front of a cylindrical water tank and has a viewing angle of 27 degrees to the sides of the tank. What percentage of the circumference of the tank can they see?

Answer 1

The central angle subtended by the visible arc is
2*(90-27/2) = 153°
so, they can see 153/360 = 42.5%

Answer 2

15

Answer 3

42.5%