Çözüldü Angles - Trigonometric Unit Circle

From the US Naval Academy's Precalculus Exams:

Find the angle below that is co-terminal with θ = −13π / 6 (i.e. points in the same direction).

A) 30°
B) 150°
C) 11π / 6
D) 13π / 6
E) None of the above

https://www.usna.edu/MathDept/_files/documents/resources/oldExams/sm005-final-fall-2016-2017.pdf (Page 5, Question 13)
Answers: https://www.usna.edu/MathDept/_file...oldExams/sm005-final-fall-2016-2017-solns.pdf

-13π / 6 = -(2π + π / 6) ====> -π / 6 Radian (4th Quadrant)

Test Rule: Start with choice C, 11π / 6 = 2π - π / 6 ====> -π / 6 Radian (4th Quadrant)

Note:
30° ====> 1th Quadrant
150° ===> 2nd Quadrant
13π / 6 = 2π + π / 6) ====> π / 6 Radian (1st Quadrant) = 30°