To figure this one out, my pre calculus teacher said to "plug and chug". Since you are adding each number to itself, A=-20, B=-10, C=0, and D=10. So your answer would be C.0
31.

32.

33.

pls mark me as brainliest
17.89, is this an option?
the answer is C................................
Angle 1 and 2 are vertical angles
Hope this helps :)