Question

How do you find the reference angle for the given angle 415?

Answer 1

A reference angle is the angle between the X-axis and the arm of some given angle and is always measured as a value in the range `[0,pi/2]` or (equivalently) `[0,90^@]`

Assuming your `415` is meant to be `415^@` (and not radians):
`color(white)("XXXX")` `415^@ = 360^@ + 55^@`

The reference angle is `55^@`