Instructional Video4:23
CK-12 Foundation

Area and Perimeter of Trapezoids: Lesson

6th - 11th Standards
With a little averaging, a trapezoid becomes a parallelogram. The section of an extensive geometry playlist shows how to derive the formula for the area of a trapezoid by changing it into a parallelogram. Using the formula, the video...
Instructional Video3:21
CK-12 Foundation

Area and Perimeter of Rectangles: Lesson

4th - 9th Standards
Around and in—take a different look at rectangles. A portion of a basic geometry playlist discusses the area and perimeters of rectangles. Using the formulas, the presentation works perimeter and area examples with rectangles and squares.
Instructional Video2:54
CK-12 Foundation

Segments from Chords: Lesson

9th - 11th Standards
Strike a chord length. The section of a larger playlist on geometry introduces the relationship relating lengths of intersecting chords. Using the relationship, the video shows how to find lengths of segments of the chords.
Instructional Video5:55
CK-12 Foundation

Inscribed Angles in Circles: Lesson

9th - 12th Standards
Circle the angles and intercept the arcs. The video introduces three theorems relating to inscribed angles in circles. Using drawings, the segment of a playlist on geometry illustrates the measure of angle along with theorems about two...
Instructional Video4:14
CK-12 Foundation

Transformation - Translation: Lesson

7th - 11th Standards
Develop a prime example of sliding about the coordinate plane. Using figures on the coordinate plane, a segment of an extensive geometry playlist introduces the transformation of translations. The presentation uses coordinate notation to...
Instructional Video3:37
CK-12 Foundation

Cones: Lesson

8th - 11th Standards
Just how much ice cream will the cone hold? The video provides the formulas to find the surface area and the volume of cones. Using example problems, the section of a geometry playlist shows how to use the formulas to find the surface...
Instructional Video2:34
CK-12 Foundation

Cylinders: Lesson

7th - 11th Standards
The solid is the same as a prism ... well, almost. The presentation makes connections between finding the volume and surface area of cylinders to prisms. Using the newly derived formulas, the portion of a large geometry playlist...
Instructional Video2:45
CK-12 Foundation

Measuring Arc Length: Lesson

7th - 11th Standards
Slice off a piece of pi! A section of an extensive playlist on geometry develops the formula to find the length of an arc. Using the formula, the presentation works through examples finding the arc length, the radius, and the measure of...
Instructional Video2:32
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1
CK-12 Foundation

Area of Composite Shapes: Lesson

6th - 10th Standards
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.
Instructional Video3:15
CK-12 Foundation

Area of a Parallelogram: Lesson

6th - 10th Standards
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.
Instructional Video3:10
CK-12 Foundation

Angles On and Inside a Circle: Lesson

9th - 11th Standards
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.
Instructional Video1:43
CK-12 Foundation

Inscribed Quadrilaterals in Circles: Lesson

9th - 11th Standards
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...
Instructional Video3:15
CK-12 Foundation

Similar Polygons and Scale Factors: Lesson

7th - 11th Standards
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...
Instructional Video4:10
CK-12 Foundation

Trigonometric Ratios with a Calculator: Lesson

9th - 12th Standards
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...
Instructional Video4:04
CK-12 Foundation

Dilation: Lesson

7th - 11th Standards
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.
Instructional Video2:56
CK-12 Foundation

Parallel Lines and Transversals: Lesson

7th - 11th Standards
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...
Instructional Video5:05
CK-12 Foundation

Proportions: Lesson

6th - 11th Standards
Proportionally, one doesn't see much of cross multiplying in geometry. The portion of extensive playlist on geometry reviews proportions. Using properties of equality, the video shows why cross multiplying works for proportions.
Instructional Video4:02
CK-12 Foundation

Classifying Parallelograms: Lesson

8th - 11th Standards
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.
Instructional Video6:07
CK-12 Foundation

Medians: Examples

8th - 11th Standards
Balance the knowledge of intersecting medians. Using examples, the portion of a geometry playlist introduces the centroid. A video describes the property of the location of the triangle medians' point of concurrency. 
Instructional Video3:07
CK-12 Foundation

Perpendicular Bisectors: Lesson

8th - 11th Standards
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.
Instructional Video4:35
CK-12 Foundation

Inverse Trigonometric Ratios: Lesson

9th - 11th Standards
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...
Instructional Video4:20
CK-12 Foundation

Indirect Measurement: Lesson

7th - 11th Standards
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...
Instructional Video4:29
CK-12 Foundation

Classifying Quadrilaterals in the Coordinate Plane: Lesson

8th - 11th Standards
Coordinate the classification of quadrilaterals. Given the definitions of special quadrilaterals, a portion of a geometry playlist highlights ways to classify a quadrilateral. The video takes information from figures on a coordinate...
Instructional Video3:41
CK-12 Foundation

Parallelograms: Lesson

8th - 11th Standards
Properties spawn from parallel sides. With the aid of diagrams, the presentation shows the different properties of parallelograms. The segment of an extensive geometry playlist lists the properties that using the parallel sides of a...