CK-12 Foundation
Ck 12: Geometry: Right Triangle Similarity Study Guide
[Free Registration/Login may be required to access all resource tools.] An overview of altitudes and geometric mean is provided in this study guide.
Texas Education Agency
Texas Gateway: Similar Right Triangles: The Altitude to the Hypotenuse
The student will apply and prove the definition of similar triangles and identify and apply the relationships that exist when an altitude is drawn to the hypotenuse of a right triangle, including the geometric mean.
Oswego City School District
Regents Exam Prep Center: Congruence of Triangles
Congruent means, "same size, same shape." Find out more about this concept at this test prep site with real world examples and pictures. Hands-on classroom activity and lots of practice. Knowledge of basic algebra and geometry concepts...
Other
The Alphabet of Art: Shape
Definition of shape as it applies to the visual arts with examples by Duchamp and McKnight. Links to definitions of other elements of art.