16. ∠2 = 53° because it is supplementary.
- You are given the measurement of ∠1, which is 128°. From the picture you can see that ∠1 and ∠2 combined equal 180° (they are supplementary angles).
- So to find ∠2, simply subtract 128° from 180°. The answer is 53°.
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17. 12° because it is vertical.
- Vertical angles, like 48° and 4x in the image, are always equal.
- So if 4x = 48°, then you can divide both sides to get x = 12°.