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.
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 altitude bisects the base and opp...
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, "
this feature of an isosceles trian...
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: 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 triangle is a right triangle, a...
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).
Area and Volume: Finding the Area of a Parallelogram or a Triangle
This clip explains that finding the area of a parallelogram is much like finding the area of a rectangle. "The area of a parallelogram equals the base times the height," the clip states. The clip further notes that, "
if we cut a parallelogram in h...
Area and Volume: Introduction to Area and Volume
This clip briefly introduces area and volume. "Area measures the surface of things that are flat," the clip explains, "such as the area of a rug. Volume measures things that occupy space, such as the volume of a freezer."
Perimeter: Finding the Perimeter When Sides Are Measured in Different Units
This clip explains that, when the sides of a polygon are stated in different units, it's necessary to convert so that they are expressed in the same units. Once this is done, the sides can be added up and the perimeter determined. The clip includes ...
Perimeter: Perimeter and Irregular Polygons
This clip explains that, "
we can find the perimeter of any polygon by adding the lengths of all sides." The clip includes practical problems and examples which demonstrate how this is done.