About: http://webisa.webdatacommons.org/319399301

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	If then Opposite Angles Theorem Converse: If the opposite angles of a quadrilateral are congruent, then the figure is a parallelogram.
http://www.w3.org/ns/prov#wasQuotedFrom	ck12.org