Trees and Other Critical Resources
Former Sierra Club president David Brower talks about the value of critical resources, including trees, soil, water and rapidly disappearing species.
Triangles: Altitude in Triangles
This clip looks at a feature of isosceles triangles that has to do with altitude (or height). "The altitude is a perpendicular line segment from the base to the vertex of the opposite angle," the clip explains. "The alti..
Triangles: Closer Look at Isosceles Triangles, A
This clip focuses on isosceles triangles, explaining that the equal sides are called the legs, while the remaining side is called the base. The clip notes that the base angles have the same measure, adding that, "Â…this ..
Triangles: Introduction to Triangles
This clip talks about the ways in which triangles are used in various professions. It also introduces the different types of triangles (equilateral, scalene and isosceles).
Triangles: Pythagorean Theorem, The
This clip introduces the Pythagorean Theorem, named for the Greek mathematician Pythagoras. In addition to explaining the theorem itself, the clip explains how it is commonly used, including as a way to determine if a tr..
Triangles: Triangles: Practical Problems
This clip consists of several practical problems which the student can solve by applying the Pythagorean Theorem and other facts about triangles that have been discussed in previous clips.
Triangles: Using the Sum of the Angles Property
This clip explains how to use the sum of the angles property of triangles to find the measure of an unknown angle when the measure of the other two angles is known.
Trouble With Tax Cuts, The
Director of the National Economic Council and former Secretary of the Treasury Lawrence Summers argues that "there are real dangers in excessively large tax cuts because of an aging society (and) because we don't know wh..
Truth
Philosopher W.V. Quine talks about truth, pointing out paradoxes that often crop up in such discussions. As an example, he cites the contradiction inherent in the sentence, "This sentence is false."
Truth Be Told: Deciding What to Study
The factors that motivate sociologists to study one thing as opposed to another are probably as numerous and varied as the sociologists themselves. A powerful motivation for some is the desire to shed light on social pro..