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Line AB is parallel to line CD. What is the measure of ∠1?

Line AB is parallel to line CD. What is the measure of ∠1?-example-1
User Davorak
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1 Answer

20 votes
20 votes

∠1 = 100° (option E)

Step-by-step explanation:

∠5 and 80 degrees are supplementary angles.

Their sum is equal to 180 degrees

∠5 + 80° = 180° (sum of angles on a line)

∠5 = 180 - 80

∠5 = 100°

The angle at the top of the first line corresponds to the the angle at the top of the 2nd line

∠5 corresponds to ∠1

Corresponding angles are equal

∠5 = ∠1

Hence, ∠1 = 100° (option E)

User Jorje Redemption
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