Prove that the opposite angles of a parallelogram are congruent. Can someone please help

Question

anonymous · Answer

attachment

zarkon · Answer

$$\angle4+\angle3=180$$
$$\angle2+\angle3=180$$

zarkon · Answer

do you agree?

anonymous · Answer

yes

zarkon · Answer

subtract the two equations

parthkohli · Answer

Or you could use the diagonal as a transversal and then use the alternate-interior angle theorem.

zarkon · Answer

that would work, but you would need to use the alternate-interior angle theorem twice

anonymous · Answer

so the given would be $$\angle 4 + \angle 3= 180 and \angle 2 + \angle 3=180$$

anonymous · Answer

i have to write is as a paragraph poof, but it doesnt show the given

jhonyy9 · Answer

so like a first step you know from a parallelogramm that the opposite sites are parallelles and congruents --- so from this resulte that these two diagonales are congruents so from this result that these opposite angles from what are frormed  these two diagonales are congruents 

hope so much that is understandably 

good luck

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