I believe it is context clues. The reader typically looks for context clues to understand the reading.
C. 118.2
1 and 2 make a complimentary angle, so 2=118.2
2 and 6 are corresponding, so angle 2=angle 6 (118.2 = 118.2)
-1 1/2 is the answer. I'm making 20 characters.
Answer:

Step-by-step explanation:
