CK-12 Foundation
Kites: Lesson
Don't just go fly a kite. The resource, part of a playlist on basic geometry, introduces the kite figure and provides examples. Using the problems, the video highlights properties of kites.
CK-12 Foundation
Indirect Measurement: Lesson
When the tape measure will not reach, use similarity. An installment of a large playlist on geometry introduces the method of indirect measurement. Using a story of finding the distance to the sun, the video shows how to use similar...
CK-12 Foundation
Triangle AA Similarity: Lesson
Two sets of congruent angles leads to three. Using diagrams of two triangles, the presentation intuitively shows that if two sets of angles are congruent, the third set is too. The portion of a geometry playlist uses that information to...
CK-12 Foundation
Parts of Circles: Lesson
Start off with the basic parts. The section of a larger playlist covering essential geometry concepts identifies and provides the definitions of the basic parts of a circles. Using drawings, the video illustrates the different parts and...
CK-12 Foundation
Inverse Trigonometric Ratios: Lesson
Finding the inverse of trigonometric ratios is not the same as finding the reciprocal. The presentation introduces how to find the angle of a right triangle given sides. Part of a larger playlist on geometry, the video uses the inverse...
CK-12 Foundation
Special Right Triangle 30-60-90: Lesson
It is special—given one length, you can find the other two. A segment of a basic geometry playlist provides the ratio of the lengths of sides of a 30-60 right triangle. The presentation shows how to use the ratio to find side lengths...
CK-12 Foundation
Special Right Triangle 45-45-90: Lesson
Square roots connect squares and right triangles. Using the Pythagorean Theorem, the video shows the relationship between the sides and hypotenuse of a 45-45 right triangle. The portion of a larger geometry playlist applies the...
CK-12 Foundation
Self Similarity: Lesson
Zoom in to reveal more of the same. The resource introduces the concept of self similarity. Using a simple example, the video—part of a larger playlist covering geometry concepts—illustrates the meaning of a self similarity figure.
CK-12 Foundation
Simplifying Radicals Review: Lesson
This work is radical! The video provides a refresher on radicals. The segment of an extensive basic geometry playlist reminds the class of the the rules for operating and simplifying expressions involving radicals.
CK-12 Foundation
Triangle Proportionality: Lesson
Look at proportionality from a parallel perspective. A section of an expansive geometry playlist introduces the Triangle Proportionality Theorem. Using the theorem, the video shows how to determine missing measurements in triangles.
CK-12 Foundation
Perpendicular Bisectors: Lesson
Get right up and split it in half. Using a diagram, the video provides the definition of a perpendicular bisector. The portion in a playlist on basic geometry explains perpendicular bisector of a segment and of triangle sides properties.
CK-12 Foundation
Classifying Parallelograms: Lesson
Properly organize parallelograms. Given special parallelograms, the narrator of a short video explains the properties of each. The section of a playlist on geometry uses the properties to classify the special parallelograms.
CK-12 Foundation
Similar Polygons and Scale Factors: Lesson
Develop an understanding of the scale of similarity. Starting with the concept of congruency, the resource introduces the idea of similarity between two figures. As part of a larger playlist on geometry, it defines similarity and uses...
CK-12 Foundation
Parallel Lines and Transversals: Lesson
Segment transversals proportionally. Given a diagram with three parallel lines and two transversals, the narrator of a short video points out the parallel lines cut the transversals proportionally. The portion of a long playlist on...
CK-12 Foundation
Dilation: Lesson
Dilation—more than just an eye opener! A short video introduces the concept of dilating a figure given a center and a scale factor. Using prime notation, the installment of a larger geometry playlist shows how to label dilated images.
CK-12 Foundation
Trigonometric Ratios with a Calculator: Lesson
Calculators ... they are more efficient than tables. Using two 30-60 right triangles, the segment of a playlist on geometry shows that trigonometric ratios for an angle are the same independent of the size of the triangle. The video...
CK-12 Foundation
Arcs in Circles: Lesson
Taking a major look at arcs is not minor. A segment of an extensive playlist on geometry introduces the concept of an arc in a circle. The resource demonstrates how to find the measure of an arc and defines special types of arcs.
CK-12 Foundation
SSS Similarity Theorem: Lesson
Judging by the sides, things appear similar. A portion of a larger playlist on geometry introduces the Side-Side-Side Similarity Theorem. The video shows how to use the lengths of sides to determine whether triangles are similar.
CK-12 Foundation
Inscribed Quadrilaterals in Circles: Lesson
Find supplementary information about inscribed angles. A section of a large geometry playlist introduces the relationship of angles in an inscribed quadrilateral. The presentation works through examples that use the relationship between...
CK-12 Foundation
Angles On and Inside a Circle: Lesson
A video introduces methods to find the measure of angles whose vertex is on and inside a circle. Within examples, the section of a larger playlist on basic geometry incorporates several angle measurement theorems.
CK-12 Foundation
Segments from Secants and Tangents: Lesson
Squaring the length equals the product of the outside times the whole. The presentation shows how to find a missing length in a tangent segment or secant segment. As part of a geometry playlist, the video provides the formula relating...
CK-12 Foundation
Area of a Parallelogram: Lesson
Sliding over a corner makes a rectangle. The resource demonstrates why the formula of the area of a parallelogram works. As part of a larger playlist on basic geometry, the video works examples dealing with parallelogram areas.
CK-12 Foundation
Area and Perimeter of Similar Polygons: Lesson
Find the square of the scale factor. A component of a large playlist on geometry discusses the ratios of the perimeters and areas of two similar polygons. The resource shows examples in finding the ratios that lead to a pattern.
CK-12 Foundation
Area of Composite Shapes: Lesson
To find the whole, add and subtract the pieces. A portion of a massive geometry playlist shows how to approach finding the area of a composite figure. The resource works with a couple different composite shapes to find their areas.