document.write( "Question 251946: I really need help. i haven't done math in 13 years. I must do a proof. There are 2 triangles. one on top of the other only the top one is upside down. My given is segment AB is parallel to segment CD. those being the bases of each triangle. I must prove the top triangle APB is similar to the lower triangle DPC. the 2 triangles are sitting tip to tip not covering each other at all. face to face if u want to call it that thanks for your help \n" ); document.write( "
Algebra.Com's Answer #183676 by solver91311(24713)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "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.\r
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\n" ); document.write( "\n" ); document.write( "BC is a transversal of the two given parallel segments, so angle B is congruent to angle C -- same reason.\r
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\n" ); document.write( "\n" ); document.write( "Angle APB is congruent to angle CPD because they are vertical angles (formed by the intersection of two straight lines)\r
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\n" ); document.write( "\n" ); document.write( "The two triangles are similar by Angle-Angle-Angle.\r
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