Circumcenter and Incenter Video from Class

http://www.youtube.com/watch?v=KvBnzeHnMR0

Point of Concurrency

http://www.brightstorm.com/math/geometry/constructions/point-of-concurrency/     (must pay...or start free trial)

Constructing the Circumcenter

http://www.brightstorm.com/math/geometry/constructions/constructing-the-circumcenter/     (must pay...or start free trial)

Constructing the Incenter

http://www.brightstorm.com/math/geometry/constructions/constructing-the-incenter/     (must pay...or start free trial)

Constructing the Centroid

http://www.brightstorm.com/math/geometry/constructions/constructing-the-centroid/    (must pay...or start free trial)

About the Orthocenter

http://www.brightstorm.com/math/geometry/constructions/constructing-the-orthocenter/   (must pay...or start free trial)

Constructing the Orthocenter

http://www.youtube.com/watch?v=7WxiMbdfQcg&feature=related