Question

Prove that the opposite angles of a parallelogram are congruent.

Answer 1

http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_1004_04/image0154e985306.gif

Answer 2

(Excuse me for my crappy drawing... solution to come)

Answer 3

i actually provided one

Answer 4

@dpgreen Yours is locked

Answer 5

oh...why is it locked?

Answer 6

@dpgreen It is a private resource of your course.

Answer 7

oh ok

Answer 8

To prove that A and D is congruent (assume all units are degrees):
A + C = 180 (int < supp, AB//CD)
C + D = 180 (int < supp, AC//BD)
Since A + C = C + D, A = D.

Answer 9

@tyteen4a03 what's int.?

Answer 10

Interior

Answer 11

//= parallel?

Answer 12

also is this the transitive property?

Answer 13

@tyteen4a03

Answer 14

@dpgreen Yes, // = parallel, and the transitive property was used in the proof.