Texas Instruments
Texas Instruments: Exploring the Orthocenter of a Triangle
In this activity, students use the Cabri Jr. tools to draw altitudes in a triangle. They construct a line perpendicular to a given line and through a given point. [Requires Adobe Reader.]
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Curated OER
Altitudes & Orthocenters: Making Connections...
This site describes altitudes and orthocenters in triangles and their connections with the nine-point circle.
Texas Instruments
Texas Instruments: Centers of a Triangle
The centroid, circumcenter, orthocenter, and incenter are the four classic centers of a triangle that are studied in geometry. In this activity, you will construct these center points and discover their properties. [Requires Adobe Reader.]
Cuemath
Cuemath: Point of Concurrency
Learn all about the point of concurrency. This lesson targets the point of concurrency of perpendicular bisectors, the point of concurrency of the angle bisectors of a triangle, and has interesting solved examples and practice questions.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Actividades Con Las Rectas De Un Triangulo
You will find an interactive activity to review the following concepts: altitude, median, angle bisector and points of concurrency in triangles. Five different interactive quizzes are also provided to test your knowledge.
CK-12 Foundation
Ck 12: Geometry: Altitudes Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept teaches students properties of altitudes of triangles and how to apply them.
Other
Gobierno De Navarra: Puntos Y Rectas Notables De Un Triangle
Learn how to construct the bisectors, median and altitude of a triangle.
CK-12 Foundation
Ck 12: Geometry: Bisectors, Medians, Altitudes Study Guide
This study guide on bisectors, medians, and altitudes covers key vocabulary, different theorems, and facts about the altitude and triangles. It is available for download with free registration.
Math Open Reference
Math Open Reference: Altitude of a Triangle
Learn about the altitude of a triangle with this handy reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Euler Line
Learn about the Euler line with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.
CK-12 Foundation
Ck 12: Interactive Geometry: 4.5 Theorems About Concurrence in Triangles
Find out about some common centers of triangles.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Triangle Altitudes
Here at the Math Forum, Dr. Math proves the concurrency of the altitudes of a triangle. Links are provided for associated topics.