∠3 and ∠4 are supplementary angles complementary angles vertical angles congruent

Answer : The are, supplementary angles.

Explanation :

Supplementary angles  : The two angles are supplementary angle in whcih the the sum of those two angle are

Complementary angles  : The two angles are complementary angle in whcih the the sum of those two angle are

Vertical angles  : Vertical angles are the angles that are opposite to each other when two lines intersect each other.

Congruent angle : It is defined as they have the same angles.

From the above information we conclude that,

, , and are the supplementary angles.

and are the vertical angles.

Hence, the are, supplementary angles.

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i think it is true since you can test the answer and can use observations to complete it.