Question 251946
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AD is a transversal of the two given parallel segments, so angle A is congruent to angle D because of the congruence of opposite interior angles.


BC is a transversal of the two given parallel segments, so angle B is congruent to angle C -- same reason.


Angle APB is congruent to angle CPD because they are vertical angles (formed by the intersection of two straight lines)


The two triangles are similar by Angle-Angle-Angle.



John
*[tex \LARGE e^{i\pi} + 1 = 0]
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