SOLUTION: In regular pentagon ABCDE, draw diagonal AC. Prove that segments AC and DE are parallel.

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Question 1201141: In regular pentagon ABCDE, draw diagonal AC. Prove that segments AC and DE are parallel.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!

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All sides of pentagon equal
Interior angles of polygon =108 deg
AB=BC in triangle ABC Isoscles triangle
AE =ED in triangle AED Isoscles triangle
Sum of anglesof triangle =180 deg
36+36+108=180 deg
Angle BAE = 108
Therefore angle CAD =36 deg
Angle BAD = angle ADE
But they are alternate angles forme by transversal AD
Therefore AC || DE