Please help AND NO LINKS OR U WILL BE REPORTED!
Identify the reference angle ∅ for each given angle, Ф.

When Ф = 300°, ∅=______degrees
When Ф = 225°, ∅=______ degrees
When Ф = 480°, ∅=______degrees
when Ф = -210°, ∅= ______ degrees