9514 1404 393
Answer:
∠7 = 142°
Explanation:
Angle 7 and the one marked 38° form a linear pair. The fact that line L exists and is parallel to line M is irrelevant to this question. Angles of a linear pair are supplementary, so ...
∠7 = 180° -38° = 142°
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Additional comment
Because lines L and M are parallel, all of the obtuse angles in this geometry have the same measure as angle 7. Likewise, all of the acute angles are congruent to 38°.
∠1 = ∠3 = ∠5 = ∠7 = 142°
∠2 = ∠4 = ∠6 = 38°