Question

Given: What type of angles are ∠2 and ∠3 are adjacent angles.

Answer 1

The correct answer is:  [D]:  "supplementary angles, 180° " .
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Note:  

Choices:
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   [B]:  "complementary angles, 180° " ; and:
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   [C]:  "supplementary angles, 90° "  ;  
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can automatically be ruled out ; since by definition:

     →  Complementary angles always add up to 90° — NOT 180° ; 
and:   supplementary angles always add up to 180° — NOT 90° .
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Note:  "Adjacent angles" refer to "supplementary angles" ; which, by definition add up to 180° .  Futhermore, looking at the image provided,

we see that ∠1 and ∠2 are, in fact "adjacent" and that ∠1 and ∠2 comprise the entire portion of a "straight line" (being intersected by a transversal)" ;  

  and as such;  ∠1 and ∠2 are supplementary angles—
 
  and as such—add up to 180° .

(which rules out:  Choice [A]:  "complementary angles, 90°) ; 

→  and demonstrates the correct answer:
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Answer choice:  [D]:  "supplementary angles, 180° " .
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