Vertical (angles)
From Biocrawler, the free encyclopedia.
A pair of angles are said to be vertical if they share the same vertex and are bounded by the same pair of lines but are opposite to each other. If a pair of angles are vertical, then they are (congruent). More precisely, if two lines AB and CD intersect at E, and E is between A and B, and E is between C and D, then angle AEC is vertical to angle BED, and angle AED is vertical to angle BEC.
