About: http://webisa.webdatacommons.org/286783714

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	As used herein, the term ???descending angle??? refers to any angle, other than 180???, between the contacting surface and the upper plane.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com