Vertical angles are just opposite each other when two segments intersect. Angles ∠*FEG* (also written ∠*GEF*) and ∠*BED* (also known as ∠*DEB*, ∠*BEC*, ∠*CEB*, ∠*AED*, ∠*DEA*, ∠*AEC*, or ∠*CEA*) are vertical angles. Another pair of vertical angles is ∠*FEB* (which is the same as ∠*FEA*, ∠*BEF*, and ∠*AEF*) and ∠*GED* (also ∠*DEG*, ∠*GEC*, or ∠*CEG*). Clearly, these angles love alter egos.
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